Gain In Semiconductor Lasers Research Articles

Gain mechanism in an (AlGa)As double heterostructure laser

Presented here is substantial evidence of a specific quantum mechanical model for gain in a (AlGa)As double heterostructure laser with a pure active layer. Close quantitative agreement between predicted and measured values substantiates a new model that evolves directly from Stern's theory. A novel method employing picosecond optical probe pulses coupled axially to the semiconductor laser gain guide allows the first direct measurements of guide gain. The concept of optical impulse response is introduced. Current spreading and facet reflectivity are directly measured. The first self-consistent set of characteristic parameters for a specific laser are determined.

Bistability and Differential Gain in Semiconductor Lasers

Bistable operation and differential gain characteristic have been achieved in the current-light output characteristics for stripe geometry InGaAsP/InP DH lasers with an inhomogeneous excitation. This device has an advantage in that the characteristics can be chosen merely by varying the stripe geometry and tuning the device temperature. Under the operating condition of bistability, switching between the two states was accomplished by applying an electrical pulse of 2.5 mA or less to the device. Switch-on time was less than 0.5 ns and switch-off time was about 1 ns. Bistable operation by optical injection is also reported. An incident optical beam, generated by a conventional DH semiconductor laser, was injected into the bistable laser. Bistability has been achieved in incident beam intensity-optical output intensity curves. The bistable laser also acted as an optical limiter.

Correction to "Theory of optical gain and threshold properties of semiconductor lasers"

Correction to "Theory of optical gain and threshold properties of semiconductor lasers"

Saturation behavior of the optical gain in GaAs injection lasers

A recent analysis of the saturation behavior of the optical gain in semiconductor lasers has predicted a strong spectral hole-burning effect. With an improved treatment of the intraband relaxation in the analysis the effect disappears entirely.

Theory of optical gain and threshold properties of semiconductor lasers

The theory of optical gain in highly doped semiconductors employed for semiconductor lasers is developed based on the Green function approach. With the help of the analytical expression obtained for optical gain, the threshold properties of semiconductor lasers and their dependence on concentration of doping impurities and on temperature are studied. Results of numerical calculations of threshold characteristics for the most interesting cases are presented.

Theory of the gain of semiconductor lasers

A theoretical, investigation is made of the laser gain associated with interband transitions in heavily doped semiconductors. Analytic expressions are obtained for the gain and quasi-Fermi levels considered as a function of the impurity concentration, temperature, and pumping power.