How to tell how sensitive a photodiode is?











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I am looking to buy some new photodiodes for a project. Currently, I have been using expensive photodiodes with a picosecond level rise and fall time and a very small area to pick up light. The problem is that I am not getting much light into the photodiode so the readings are quite low and need to have more of a range.



I was just wondering what the measurement for how sensitive a photodiode is and if anyone has any good ideas for near-infrared (800-850 nm) photodiodes which are extremely sensitive so have a large range from not much light which is what I need.



This is the type of photodiode I am looking for: https://www.mouser.co.uk/ProductDetail/OSRAM-Opto-Semiconductors/BPX-65?qs=sGAEpiMZZMtWNtIk7yMEsZEKXNTNxzvb%2fe6wSDgXefo%3d



Any ideas?
Thanks in advance










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  • Related: Influence of active area of photo diode on sensitivity
    – The Photon
    2 hours ago










  • Michel Keijzers - I appreciate your efforts, but photodiode is one word. So is picosecond.
    – WhatRoughBeast
    1 hour ago

















up vote
3
down vote

favorite












I am looking to buy some new photodiodes for a project. Currently, I have been using expensive photodiodes with a picosecond level rise and fall time and a very small area to pick up light. The problem is that I am not getting much light into the photodiode so the readings are quite low and need to have more of a range.



I was just wondering what the measurement for how sensitive a photodiode is and if anyone has any good ideas for near-infrared (800-850 nm) photodiodes which are extremely sensitive so have a large range from not much light which is what I need.



This is the type of photodiode I am looking for: https://www.mouser.co.uk/ProductDetail/OSRAM-Opto-Semiconductors/BPX-65?qs=sGAEpiMZZMtWNtIk7yMEsZEKXNTNxzvb%2fe6wSDgXefo%3d



Any ideas?
Thanks in advance










share|improve this question









New contributor




tester questions is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.




















  • Related: Influence of active area of photo diode on sensitivity
    – The Photon
    2 hours ago










  • Michel Keijzers - I appreciate your efforts, but photodiode is one word. So is picosecond.
    – WhatRoughBeast
    1 hour ago















up vote
3
down vote

favorite









up vote
3
down vote

favorite











I am looking to buy some new photodiodes for a project. Currently, I have been using expensive photodiodes with a picosecond level rise and fall time and a very small area to pick up light. The problem is that I am not getting much light into the photodiode so the readings are quite low and need to have more of a range.



I was just wondering what the measurement for how sensitive a photodiode is and if anyone has any good ideas for near-infrared (800-850 nm) photodiodes which are extremely sensitive so have a large range from not much light which is what I need.



This is the type of photodiode I am looking for: https://www.mouser.co.uk/ProductDetail/OSRAM-Opto-Semiconductors/BPX-65?qs=sGAEpiMZZMtWNtIk7yMEsZEKXNTNxzvb%2fe6wSDgXefo%3d



Any ideas?
Thanks in advance










share|improve this question









New contributor




tester questions is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.











I am looking to buy some new photodiodes for a project. Currently, I have been using expensive photodiodes with a picosecond level rise and fall time and a very small area to pick up light. The problem is that I am not getting much light into the photodiode so the readings are quite low and need to have more of a range.



I was just wondering what the measurement for how sensitive a photodiode is and if anyone has any good ideas for near-infrared (800-850 nm) photodiodes which are extremely sensitive so have a large range from not much light which is what I need.



This is the type of photodiode I am looking for: https://www.mouser.co.uk/ProductDetail/OSRAM-Opto-Semiconductors/BPX-65?qs=sGAEpiMZZMtWNtIk7yMEsZEKXNTNxzvb%2fe6wSDgXefo%3d



Any ideas?
Thanks in advance







sensor infrared photodiode light-sensor






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tester questions is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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share|improve this question









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share|improve this question




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edited 1 hour ago









WhatRoughBeast

48.8k22873




48.8k22873






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tester questions is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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tester questions is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.






tester questions is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.












  • Related: Influence of active area of photo diode on sensitivity
    – The Photon
    2 hours ago










  • Michel Keijzers - I appreciate your efforts, but photodiode is one word. So is picosecond.
    – WhatRoughBeast
    1 hour ago




















  • Related: Influence of active area of photo diode on sensitivity
    – The Photon
    2 hours ago










  • Michel Keijzers - I appreciate your efforts, but photodiode is one word. So is picosecond.
    – WhatRoughBeast
    1 hour ago


















Related: Influence of active area of photo diode on sensitivity
– The Photon
2 hours ago




Related: Influence of active area of photo diode on sensitivity
– The Photon
2 hours ago












Michel Keijzers - I appreciate your efforts, but photodiode is one word. So is picosecond.
– WhatRoughBeast
1 hour ago






Michel Keijzers - I appreciate your efforts, but photodiode is one word. So is picosecond.
– WhatRoughBeast
1 hour ago












3 Answers
3






active

oldest

votes

















up vote
5
down vote













Depending on the speed you need, you may well be out of luck.



You state that your current diodes "with a pico second level rise and fall time", while you link to a PD with 12 nsec rise and fall times. Furthermore, you say that your PDs are "expensive ", but the linked units are only about 6 bucks in onesies, and if you think 6 bucks is expensive for a photo diode, I suggest you need to do some research. Try Digikey or Mouser. So it's not really clear exactly what photo diodes you are talking about.



With that said, silicon photo diodes all have pretty much the same maximum sensitivity, .55 to .65 A/W. And you only get high speed by reducing the capacitance of the chip, which means low sensitivity. So you basically have 3 options.




  1. Go to a bigger PD and accept the lower speed. While you have been using very fast units, you have not actually justified your need for speed, so this may be an acceptable course of action. How much speed do you really need?


  2. If you really and truly need nano second rise and fall times, keep your current diode and provide a collection lens to increase the amount of light incident on the PD. Yes, this means you'll need to redesign your apparatus, and learn some optics, but that should not be an insuperable problem.


  3. Go to an APD (avalanche photo diode). These will respond to lower light levels, and you can get fairly fast units. Of course, you'll also need to learn how to drive the little buggers, but think of it as a learning experience.







share|improve this answer























  • Hi, Thanks for the reply. These aren't the photodiodes I was using I can't find the ones I was using but they cost about $150 each. I don't need Picosecond level just nanosecond level. I just need near-infrared photodiodes which are sensitive to very low levels of infrared light.
    – tester questions
    2 hours ago










  • Sensitive photodiodes are big photodiodes. Big photodiodes are slow photodiodes. Increasing your light collection and/or generation are about the only options available. Or use something other than photodiodes, like APDs.
    – WhatRoughBeast
    1 hour ago


















up vote
3
down vote














How to tell how sensitive a photodiode is?




There's a curve in your device's datasheet that tells you exactly that:



enter image description here



Combined with the line in the Characteristics table that tells you the sensitivity is 0.55 A/W at 850 nm, this gives you the sensitivity at whatever wavelength you are using.



(Note: in the optical communications field, we'd call this a responsivity curve, not a sensitivity curve. For us, sensitivity is a measure of the minimum detectable signal)




if anyone has any good ideas for near-infrared (800-850 nm) photo diodes which are extremely sensitive so have a large range from not much light which is what I need.




Standard p-i-n photodiodes can't produce more than one carrier pair per photon absorbed, so you won't find any with a dramatically stronger response than this one.



If you are working at one specific wavelength, you might be able to find or custom-order one with an anti-reflective (AR) coating for that wavelength and get near a 25% improvement in responsivity (based on the 80% quantum efficiency spec for this device). This will increase the cost.



Some other solutions:



As others have said, you can use an avalanche photodiode (APD), which has an internal current gain process to effectively increase the responsivity above 1 carrier pair per photon. However these require very carefully controlled high-voltage bias, which will increase your system cost.



Or, if your problem is actually focusing your light beam onto the small device area, you could use a larger device (which will be slower and will tend to be more expensive).



Finally, a solution that hasn't been suggested yet in another answer: You could be sure your light source is chosen to match the peak responsivity wavelength of your O/E.



Another comment: The Mouser page you linked calls this a phototransistor, but the Osram datasheet just calls it a photodiode, and its responsivity is typical for photodiodes, not phototransistors. Another way you can get internal gain in the device is to use an actual phototransistor. I don't use these devices regularly, but I expect they might be relatively slow compared to ordinary photodiodes.






share|improve this answer






























    up vote
    1
    down vote














    I was just wondering what the measurement for how sensitive a
    photodiode is




    The spectral sensitivity is quoted in the data sheet as 0.55 amps per watt so, if you could illuminate the sensitive area (1 sq mm) with 1 milliwatt of light at about 860 nm you'd get 0.55 milliamps produced at the output. The graphs in the data sheet show how this falls away for different light wavelengths.




    anyone has any good ideas for near-infrared (800-850nm) photodiodes
    which are extremely sensitive so have a large range from not much
    light which is what I need




    Requests for product recommendations are off-topic. However, you'll always get more signal with a bigger sensitive area but the speed will be proportionally slower.






    share|improve this answer





















    • Perfect, Thank you very much I will look more into it.
      – tester questions
      4 hours ago










    • You might want to read this being as you are a newbie.
      – Andy aka
      4 hours ago













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    3 Answers
    3






    active

    oldest

    votes








    3 Answers
    3






    active

    oldest

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    active

    oldest

    votes






    active

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    up vote
    5
    down vote













    Depending on the speed you need, you may well be out of luck.



    You state that your current diodes "with a pico second level rise and fall time", while you link to a PD with 12 nsec rise and fall times. Furthermore, you say that your PDs are "expensive ", but the linked units are only about 6 bucks in onesies, and if you think 6 bucks is expensive for a photo diode, I suggest you need to do some research. Try Digikey or Mouser. So it's not really clear exactly what photo diodes you are talking about.



    With that said, silicon photo diodes all have pretty much the same maximum sensitivity, .55 to .65 A/W. And you only get high speed by reducing the capacitance of the chip, which means low sensitivity. So you basically have 3 options.




    1. Go to a bigger PD and accept the lower speed. While you have been using very fast units, you have not actually justified your need for speed, so this may be an acceptable course of action. How much speed do you really need?


    2. If you really and truly need nano second rise and fall times, keep your current diode and provide a collection lens to increase the amount of light incident on the PD. Yes, this means you'll need to redesign your apparatus, and learn some optics, but that should not be an insuperable problem.


    3. Go to an APD (avalanche photo diode). These will respond to lower light levels, and you can get fairly fast units. Of course, you'll also need to learn how to drive the little buggers, but think of it as a learning experience.







    share|improve this answer























    • Hi, Thanks for the reply. These aren't the photodiodes I was using I can't find the ones I was using but they cost about $150 each. I don't need Picosecond level just nanosecond level. I just need near-infrared photodiodes which are sensitive to very low levels of infrared light.
      – tester questions
      2 hours ago










    • Sensitive photodiodes are big photodiodes. Big photodiodes are slow photodiodes. Increasing your light collection and/or generation are about the only options available. Or use something other than photodiodes, like APDs.
      – WhatRoughBeast
      1 hour ago















    up vote
    5
    down vote













    Depending on the speed you need, you may well be out of luck.



    You state that your current diodes "with a pico second level rise and fall time", while you link to a PD with 12 nsec rise and fall times. Furthermore, you say that your PDs are "expensive ", but the linked units are only about 6 bucks in onesies, and if you think 6 bucks is expensive for a photo diode, I suggest you need to do some research. Try Digikey or Mouser. So it's not really clear exactly what photo diodes you are talking about.



    With that said, silicon photo diodes all have pretty much the same maximum sensitivity, .55 to .65 A/W. And you only get high speed by reducing the capacitance of the chip, which means low sensitivity. So you basically have 3 options.




    1. Go to a bigger PD and accept the lower speed. While you have been using very fast units, you have not actually justified your need for speed, so this may be an acceptable course of action. How much speed do you really need?


    2. If you really and truly need nano second rise and fall times, keep your current diode and provide a collection lens to increase the amount of light incident on the PD. Yes, this means you'll need to redesign your apparatus, and learn some optics, but that should not be an insuperable problem.


    3. Go to an APD (avalanche photo diode). These will respond to lower light levels, and you can get fairly fast units. Of course, you'll also need to learn how to drive the little buggers, but think of it as a learning experience.







    share|improve this answer























    • Hi, Thanks for the reply. These aren't the photodiodes I was using I can't find the ones I was using but they cost about $150 each. I don't need Picosecond level just nanosecond level. I just need near-infrared photodiodes which are sensitive to very low levels of infrared light.
      – tester questions
      2 hours ago










    • Sensitive photodiodes are big photodiodes. Big photodiodes are slow photodiodes. Increasing your light collection and/or generation are about the only options available. Or use something other than photodiodes, like APDs.
      – WhatRoughBeast
      1 hour ago













    up vote
    5
    down vote










    up vote
    5
    down vote









    Depending on the speed you need, you may well be out of luck.



    You state that your current diodes "with a pico second level rise and fall time", while you link to a PD with 12 nsec rise and fall times. Furthermore, you say that your PDs are "expensive ", but the linked units are only about 6 bucks in onesies, and if you think 6 bucks is expensive for a photo diode, I suggest you need to do some research. Try Digikey or Mouser. So it's not really clear exactly what photo diodes you are talking about.



    With that said, silicon photo diodes all have pretty much the same maximum sensitivity, .55 to .65 A/W. And you only get high speed by reducing the capacitance of the chip, which means low sensitivity. So you basically have 3 options.




    1. Go to a bigger PD and accept the lower speed. While you have been using very fast units, you have not actually justified your need for speed, so this may be an acceptable course of action. How much speed do you really need?


    2. If you really and truly need nano second rise and fall times, keep your current diode and provide a collection lens to increase the amount of light incident on the PD. Yes, this means you'll need to redesign your apparatus, and learn some optics, but that should not be an insuperable problem.


    3. Go to an APD (avalanche photo diode). These will respond to lower light levels, and you can get fairly fast units. Of course, you'll also need to learn how to drive the little buggers, but think of it as a learning experience.







    share|improve this answer














    Depending on the speed you need, you may well be out of luck.



    You state that your current diodes "with a pico second level rise and fall time", while you link to a PD with 12 nsec rise and fall times. Furthermore, you say that your PDs are "expensive ", but the linked units are only about 6 bucks in onesies, and if you think 6 bucks is expensive for a photo diode, I suggest you need to do some research. Try Digikey or Mouser. So it's not really clear exactly what photo diodes you are talking about.



    With that said, silicon photo diodes all have pretty much the same maximum sensitivity, .55 to .65 A/W. And you only get high speed by reducing the capacitance of the chip, which means low sensitivity. So you basically have 3 options.




    1. Go to a bigger PD and accept the lower speed. While you have been using very fast units, you have not actually justified your need for speed, so this may be an acceptable course of action. How much speed do you really need?


    2. If you really and truly need nano second rise and fall times, keep your current diode and provide a collection lens to increase the amount of light incident on the PD. Yes, this means you'll need to redesign your apparatus, and learn some optics, but that should not be an insuperable problem.


    3. Go to an APD (avalanche photo diode). These will respond to lower light levels, and you can get fairly fast units. Of course, you'll also need to learn how to drive the little buggers, but think of it as a learning experience.








    share|improve this answer














    share|improve this answer



    share|improve this answer








    edited 3 hours ago









    Michel Keijzers

    5,58882461




    5,58882461










    answered 4 hours ago









    WhatRoughBeast

    48.8k22873




    48.8k22873












    • Hi, Thanks for the reply. These aren't the photodiodes I was using I can't find the ones I was using but they cost about $150 each. I don't need Picosecond level just nanosecond level. I just need near-infrared photodiodes which are sensitive to very low levels of infrared light.
      – tester questions
      2 hours ago










    • Sensitive photodiodes are big photodiodes. Big photodiodes are slow photodiodes. Increasing your light collection and/or generation are about the only options available. Or use something other than photodiodes, like APDs.
      – WhatRoughBeast
      1 hour ago


















    • Hi, Thanks for the reply. These aren't the photodiodes I was using I can't find the ones I was using but they cost about $150 each. I don't need Picosecond level just nanosecond level. I just need near-infrared photodiodes which are sensitive to very low levels of infrared light.
      – tester questions
      2 hours ago










    • Sensitive photodiodes are big photodiodes. Big photodiodes are slow photodiodes. Increasing your light collection and/or generation are about the only options available. Or use something other than photodiodes, like APDs.
      – WhatRoughBeast
      1 hour ago
















    Hi, Thanks for the reply. These aren't the photodiodes I was using I can't find the ones I was using but they cost about $150 each. I don't need Picosecond level just nanosecond level. I just need near-infrared photodiodes which are sensitive to very low levels of infrared light.
    – tester questions
    2 hours ago




    Hi, Thanks for the reply. These aren't the photodiodes I was using I can't find the ones I was using but they cost about $150 each. I don't need Picosecond level just nanosecond level. I just need near-infrared photodiodes which are sensitive to very low levels of infrared light.
    – tester questions
    2 hours ago












    Sensitive photodiodes are big photodiodes. Big photodiodes are slow photodiodes. Increasing your light collection and/or generation are about the only options available. Or use something other than photodiodes, like APDs.
    – WhatRoughBeast
    1 hour ago




    Sensitive photodiodes are big photodiodes. Big photodiodes are slow photodiodes. Increasing your light collection and/or generation are about the only options available. Or use something other than photodiodes, like APDs.
    – WhatRoughBeast
    1 hour ago












    up vote
    3
    down vote














    How to tell how sensitive a photodiode is?




    There's a curve in your device's datasheet that tells you exactly that:



    enter image description here



    Combined with the line in the Characteristics table that tells you the sensitivity is 0.55 A/W at 850 nm, this gives you the sensitivity at whatever wavelength you are using.



    (Note: in the optical communications field, we'd call this a responsivity curve, not a sensitivity curve. For us, sensitivity is a measure of the minimum detectable signal)




    if anyone has any good ideas for near-infrared (800-850 nm) photo diodes which are extremely sensitive so have a large range from not much light which is what I need.




    Standard p-i-n photodiodes can't produce more than one carrier pair per photon absorbed, so you won't find any with a dramatically stronger response than this one.



    If you are working at one specific wavelength, you might be able to find or custom-order one with an anti-reflective (AR) coating for that wavelength and get near a 25% improvement in responsivity (based on the 80% quantum efficiency spec for this device). This will increase the cost.



    Some other solutions:



    As others have said, you can use an avalanche photodiode (APD), which has an internal current gain process to effectively increase the responsivity above 1 carrier pair per photon. However these require very carefully controlled high-voltage bias, which will increase your system cost.



    Or, if your problem is actually focusing your light beam onto the small device area, you could use a larger device (which will be slower and will tend to be more expensive).



    Finally, a solution that hasn't been suggested yet in another answer: You could be sure your light source is chosen to match the peak responsivity wavelength of your O/E.



    Another comment: The Mouser page you linked calls this a phototransistor, but the Osram datasheet just calls it a photodiode, and its responsivity is typical for photodiodes, not phototransistors. Another way you can get internal gain in the device is to use an actual phototransistor. I don't use these devices regularly, but I expect they might be relatively slow compared to ordinary photodiodes.






    share|improve this answer



























      up vote
      3
      down vote














      How to tell how sensitive a photodiode is?




      There's a curve in your device's datasheet that tells you exactly that:



      enter image description here



      Combined with the line in the Characteristics table that tells you the sensitivity is 0.55 A/W at 850 nm, this gives you the sensitivity at whatever wavelength you are using.



      (Note: in the optical communications field, we'd call this a responsivity curve, not a sensitivity curve. For us, sensitivity is a measure of the minimum detectable signal)




      if anyone has any good ideas for near-infrared (800-850 nm) photo diodes which are extremely sensitive so have a large range from not much light which is what I need.




      Standard p-i-n photodiodes can't produce more than one carrier pair per photon absorbed, so you won't find any with a dramatically stronger response than this one.



      If you are working at one specific wavelength, you might be able to find or custom-order one with an anti-reflective (AR) coating for that wavelength and get near a 25% improvement in responsivity (based on the 80% quantum efficiency spec for this device). This will increase the cost.



      Some other solutions:



      As others have said, you can use an avalanche photodiode (APD), which has an internal current gain process to effectively increase the responsivity above 1 carrier pair per photon. However these require very carefully controlled high-voltage bias, which will increase your system cost.



      Or, if your problem is actually focusing your light beam onto the small device area, you could use a larger device (which will be slower and will tend to be more expensive).



      Finally, a solution that hasn't been suggested yet in another answer: You could be sure your light source is chosen to match the peak responsivity wavelength of your O/E.



      Another comment: The Mouser page you linked calls this a phototransistor, but the Osram datasheet just calls it a photodiode, and its responsivity is typical for photodiodes, not phototransistors. Another way you can get internal gain in the device is to use an actual phototransistor. I don't use these devices regularly, but I expect they might be relatively slow compared to ordinary photodiodes.






      share|improve this answer

























        up vote
        3
        down vote










        up vote
        3
        down vote










        How to tell how sensitive a photodiode is?




        There's a curve in your device's datasheet that tells you exactly that:



        enter image description here



        Combined with the line in the Characteristics table that tells you the sensitivity is 0.55 A/W at 850 nm, this gives you the sensitivity at whatever wavelength you are using.



        (Note: in the optical communications field, we'd call this a responsivity curve, not a sensitivity curve. For us, sensitivity is a measure of the minimum detectable signal)




        if anyone has any good ideas for near-infrared (800-850 nm) photo diodes which are extremely sensitive so have a large range from not much light which is what I need.




        Standard p-i-n photodiodes can't produce more than one carrier pair per photon absorbed, so you won't find any with a dramatically stronger response than this one.



        If you are working at one specific wavelength, you might be able to find or custom-order one with an anti-reflective (AR) coating for that wavelength and get near a 25% improvement in responsivity (based on the 80% quantum efficiency spec for this device). This will increase the cost.



        Some other solutions:



        As others have said, you can use an avalanche photodiode (APD), which has an internal current gain process to effectively increase the responsivity above 1 carrier pair per photon. However these require very carefully controlled high-voltage bias, which will increase your system cost.



        Or, if your problem is actually focusing your light beam onto the small device area, you could use a larger device (which will be slower and will tend to be more expensive).



        Finally, a solution that hasn't been suggested yet in another answer: You could be sure your light source is chosen to match the peak responsivity wavelength of your O/E.



        Another comment: The Mouser page you linked calls this a phototransistor, but the Osram datasheet just calls it a photodiode, and its responsivity is typical for photodiodes, not phototransistors. Another way you can get internal gain in the device is to use an actual phototransistor. I don't use these devices regularly, but I expect they might be relatively slow compared to ordinary photodiodes.






        share|improve this answer















        How to tell how sensitive a photodiode is?




        There's a curve in your device's datasheet that tells you exactly that:



        enter image description here



        Combined with the line in the Characteristics table that tells you the sensitivity is 0.55 A/W at 850 nm, this gives you the sensitivity at whatever wavelength you are using.



        (Note: in the optical communications field, we'd call this a responsivity curve, not a sensitivity curve. For us, sensitivity is a measure of the minimum detectable signal)




        if anyone has any good ideas for near-infrared (800-850 nm) photo diodes which are extremely sensitive so have a large range from not much light which is what I need.




        Standard p-i-n photodiodes can't produce more than one carrier pair per photon absorbed, so you won't find any with a dramatically stronger response than this one.



        If you are working at one specific wavelength, you might be able to find or custom-order one with an anti-reflective (AR) coating for that wavelength and get near a 25% improvement in responsivity (based on the 80% quantum efficiency spec for this device). This will increase the cost.



        Some other solutions:



        As others have said, you can use an avalanche photodiode (APD), which has an internal current gain process to effectively increase the responsivity above 1 carrier pair per photon. However these require very carefully controlled high-voltage bias, which will increase your system cost.



        Or, if your problem is actually focusing your light beam onto the small device area, you could use a larger device (which will be slower and will tend to be more expensive).



        Finally, a solution that hasn't been suggested yet in another answer: You could be sure your light source is chosen to match the peak responsivity wavelength of your O/E.



        Another comment: The Mouser page you linked calls this a phototransistor, but the Osram datasheet just calls it a photodiode, and its responsivity is typical for photodiodes, not phototransistors. Another way you can get internal gain in the device is to use an actual phototransistor. I don't use these devices regularly, but I expect they might be relatively slow compared to ordinary photodiodes.







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited 2 hours ago

























        answered 2 hours ago









        The Photon

        82.2k396194




        82.2k396194






















            up vote
            1
            down vote














            I was just wondering what the measurement for how sensitive a
            photodiode is




            The spectral sensitivity is quoted in the data sheet as 0.55 amps per watt so, if you could illuminate the sensitive area (1 sq mm) with 1 milliwatt of light at about 860 nm you'd get 0.55 milliamps produced at the output. The graphs in the data sheet show how this falls away for different light wavelengths.




            anyone has any good ideas for near-infrared (800-850nm) photodiodes
            which are extremely sensitive so have a large range from not much
            light which is what I need




            Requests for product recommendations are off-topic. However, you'll always get more signal with a bigger sensitive area but the speed will be proportionally slower.






            share|improve this answer





















            • Perfect, Thank you very much I will look more into it.
              – tester questions
              4 hours ago










            • You might want to read this being as you are a newbie.
              – Andy aka
              4 hours ago

















            up vote
            1
            down vote














            I was just wondering what the measurement for how sensitive a
            photodiode is




            The spectral sensitivity is quoted in the data sheet as 0.55 amps per watt so, if you could illuminate the sensitive area (1 sq mm) with 1 milliwatt of light at about 860 nm you'd get 0.55 milliamps produced at the output. The graphs in the data sheet show how this falls away for different light wavelengths.




            anyone has any good ideas for near-infrared (800-850nm) photodiodes
            which are extremely sensitive so have a large range from not much
            light which is what I need




            Requests for product recommendations are off-topic. However, you'll always get more signal with a bigger sensitive area but the speed will be proportionally slower.






            share|improve this answer





















            • Perfect, Thank you very much I will look more into it.
              – tester questions
              4 hours ago










            • You might want to read this being as you are a newbie.
              – Andy aka
              4 hours ago















            up vote
            1
            down vote










            up vote
            1
            down vote










            I was just wondering what the measurement for how sensitive a
            photodiode is




            The spectral sensitivity is quoted in the data sheet as 0.55 amps per watt so, if you could illuminate the sensitive area (1 sq mm) with 1 milliwatt of light at about 860 nm you'd get 0.55 milliamps produced at the output. The graphs in the data sheet show how this falls away for different light wavelengths.




            anyone has any good ideas for near-infrared (800-850nm) photodiodes
            which are extremely sensitive so have a large range from not much
            light which is what I need




            Requests for product recommendations are off-topic. However, you'll always get more signal with a bigger sensitive area but the speed will be proportionally slower.






            share|improve this answer













            I was just wondering what the measurement for how sensitive a
            photodiode is




            The spectral sensitivity is quoted in the data sheet as 0.55 amps per watt so, if you could illuminate the sensitive area (1 sq mm) with 1 milliwatt of light at about 860 nm you'd get 0.55 milliamps produced at the output. The graphs in the data sheet show how this falls away for different light wavelengths.




            anyone has any good ideas for near-infrared (800-850nm) photodiodes
            which are extremely sensitive so have a large range from not much
            light which is what I need




            Requests for product recommendations are off-topic. However, you'll always get more signal with a bigger sensitive area but the speed will be proportionally slower.







            share|improve this answer












            share|improve this answer



            share|improve this answer










            answered 5 hours ago









            Andy aka

            237k10173405




            237k10173405












            • Perfect, Thank you very much I will look more into it.
              – tester questions
              4 hours ago










            • You might want to read this being as you are a newbie.
              – Andy aka
              4 hours ago




















            • Perfect, Thank you very much I will look more into it.
              – tester questions
              4 hours ago










            • You might want to read this being as you are a newbie.
              – Andy aka
              4 hours ago


















            Perfect, Thank you very much I will look more into it.
            – tester questions
            4 hours ago




            Perfect, Thank you very much I will look more into it.
            – tester questions
            4 hours ago












            You might want to read this being as you are a newbie.
            – Andy aka
            4 hours ago






            You might want to read this being as you are a newbie.
            – Andy aka
            4 hours ago












            tester questions is a new contributor. Be nice, and check out our Code of Conduct.










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            tester questions is a new contributor. Be nice, and check out our Code of Conduct.













            tester questions is a new contributor. Be nice, and check out our Code of Conduct.












            tester questions is a new contributor. Be nice, and check out our Code of Conduct.
















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