visionsofeden
New Member
Hi,
i would like to build a laser detector to detect exact position (X,Y) of an object passing through a laser curtain.
The problem is that i need a great precision and i don't know what to use as photodetector to accomplish my goal .
The source of light will be a IR LD , followed by a beam expander and a collimating lens , to generate a laser curtain of a certain width.
At the opposite side i thought to place some sort of IR detector , but since i need to measure object position with a precision in the 100 micrometers range (0.1 mm), i don't know what could be used as photodetector that is easily available and that can reach that precision .
Another requirement would be a high scanning speed , in the scale of microseconds .
I thought about using CCDs but they are expensive and not so fast in response . Same thing for CIS .
Another option could be lateral effect photodiodes , but since i need to scan an area of apprx 20cm i could not find a sensor that match my requirements . Also i think that such a sensor would costs hundreds $ .
Photodiodes itself are quile fasts , some of them could be operated with nanoscale timings , but the problem is that i need a wide sensitive area and i could not arrange many high speed photodiodes in an array , because there will be gaps between them, because of the packaging beiing larger than single sensitive area and because normal high speed photodiodes are not guarantee to have a spatially uniform responsivity.
Could someone give me some hints about what could be used to make such a detector ?
Thanks .
Nicola.
i would like to build a laser detector to detect exact position (X,Y) of an object passing through a laser curtain.
The problem is that i need a great precision and i don't know what to use as photodetector to accomplish my goal .
The source of light will be a IR LD , followed by a beam expander and a collimating lens , to generate a laser curtain of a certain width.
At the opposite side i thought to place some sort of IR detector , but since i need to measure object position with a precision in the 100 micrometers range (0.1 mm), i don't know what could be used as photodetector that is easily available and that can reach that precision .
Another requirement would be a high scanning speed , in the scale of microseconds .
I thought about using CCDs but they are expensive and not so fast in response . Same thing for CIS .
Another option could be lateral effect photodiodes , but since i need to scan an area of apprx 20cm i could not find a sensor that match my requirements . Also i think that such a sensor would costs hundreds $ .
Photodiodes itself are quile fasts , some of them could be operated with nanoscale timings , but the problem is that i need a wide sensitive area and i could not arrange many high speed photodiodes in an array , because there will be gaps between them, because of the packaging beiing larger than single sensitive area and because normal high speed photodiodes are not guarantee to have a spatially uniform responsivity.
Could someone give me some hints about what could be used to make such a detector ?
Thanks .
Nicola.