Determination of Gain and Loss Mechanisms in Semiconductor Lasers Using Pressure Techniques

Both the gain and loss mechanisms in semiconductor lasers are determined in large part by the band structure of the laser active region and the surrounding material layers. Uniaxial stress measurements confirm the predicted variation of gain and threshold characteristics due to the incorporation of axial strain, with large tensile or compressive strain reducing the carrier and current density required to reach threshold. The combination of hydrostatic pressure measurements and band structure calculations enables identification of the dominant loss mechanisms in semiconductor lasers, identifying leakage from the active to the cladding region as the dominant loss mechanism in GaInP/AIGaInP visible lasers, and Auger recombination as the dominant loss mechanism and cause of the temperature sensitivity of long wavelength (1.3 to 1.55 μm) lasers.