Is this a IR-Filter?

[laserpointersarecool]

So recently i opened my broken green laser pointer since i already got a new one. I was interested of what is in there and what broke. It was the lasercrystal fallen off. But i found a black thing in the area where the laser crystal was. The black thing has something like a thin slice of glass attachet to it. It seems broken as well. Is this black thing a IR-filter?

 

[laserpointersarecool]

 

[laserpointersarecool]

so i tested it with a remote for LED-strips and my phone-camera since it sees IR. it is a IR filter. the IR light is blocked good.

 

[RA_pierce]

Yes, it's an IR filter. Some 532 nm DPSS lasers will use the IR Filter to direct a portion of the beam to a photodiode for optical feedback to monitor and control the power output. I've seen this most often in low-power lasers, where the output needs to be maintained below 5 mW due to government regulations. Usually in those lasers, the filter is set at an angle on the black plastic mount and the photodiode is attached perpendicular to the output beam path.