What are the most commonly used materials for Laser Diodes ?

Most commonly used materials for semiconductor lasers are the III-V compounds. These are such as GaAs, AlGaAs, InGaAs and InGaAsP depending upon the desired lasing wavelength emission.
Recently, GaN/AlGaN and InGaN/AlGaN are  being used to achieve laser diode emission in the green blue and ultraviolet regions.
InGaN (indium-gallium-nitride) is used for direct green laser diode emission.
Blue Diode Lasers (blue semiconductor laser diodes) are typically fabricated out of aluminum gallium nitride (AlGaN) or aluminum indium gallium nitride (AlInGaN).
Violet 405nm laser diodes and 375 nm UV laser diodes are based on either gallium nitride or indium gallium nitride.

What are the Typical Laser Diode Parameters ?

Threshold Current
:  The lowest current at which lasing action takes place.

Operating Current : Ideal laser diode operating current

Operating Voltage : The voltage across the laser diode at the specified operating current.

Wavelength : The output wavelength can vary from sample-to-sample and due to temperature.

Radiation Angle : The beam divergence parallel (horizontal) and perpendicular (vertical) relative to the gain region of the laser diode.

Positional and Angular Accuracy : The tolerance in mounting of the laser diode chip.

Differential Efficiency : Once the current threshold has been exceeded, the incremental increase in output power with current is fairly linear, measured in mW/mA. However, it can vary widely from sample-to-sample and with changes in temperature.

Astigmatism : The difference in virtual point source of the parallel and perpendicular beams.

Laser Diode Monitor Current : Sensitivity of the monitor photodiode with respect to laser diode output power.

Multi-wavelength optical determination of black and brown carbon in atmospheric aerosols

D Massabò, L Caponi, V Bernardoni, MC Bove… – Atmospheric …, 2015 – Elsevier
… In the new configuration, two laser diodes with λ = 375 nm and 532 nm (World Star Tech) have
been added. A motorized stage has been added to interchange the laser sources thus improving
the system stability and reproducibility and facilitating the analysis of many samples. …