This is 1655nm Long-wavelength IR Laser. It is a fiber-coupled laser, the fiber is pluggable, and the laser head has an SMA905 interface. 1655nm is not a commonly used wavelength, and the spectral width of lasers made by 1655nm chips is relatively large. The 1655nm laser is infrared invisible light, and a weak spot can be seen on the infrared photosensitive film. Check out the laser output at the fiber end.
The laser output power can be adjusted by adjusting the current.
To adjust the working current, turn the ‘Adjustor’ knob clockwise, when the current exceeds the minimum working current, the laser indicator turns green, and there is laser output at this time. ‘Adjustor’ rotates clockwise to the end, which is the max working current and the maximum output power of the laser.
This is the spectrogram of the 1655nm laser test.