Got IR filter from webcam I use for my astronomic telescope. I use it without the lens .. and the IR filter was too obviously glued to the lens. It's small glass rectangle with red/green tint. I prayed it out, and lightly glued it inside front lens cover piece. Works like a charm. Also the camera (with the lens back on) can be now used for detecting IR leakage of green lasers. I will make some pictures next time I dismantle the laser (which I don't really want, as I already twisted the diode electrodes off once .. and spent some hard time soldering them back.