Effect of Franz–Keldysh absorption on the short optical pulse generation in Transistor Laser

Abstract

In this work, the effect of Franz–Keldysh (FK) absorption on the short optical pulse generation in Transistor Laser (TL) is analyzed. Franz–Keldysh (F–K) Absorption coefficient is incorporated in the rate equations and solved numerically by fourth order Runge–Kutta (R–K) method. Short optical pulses are generated for various values of collector to base voltage. The output optical power is found to decrease with increasing reverse collector to base voltage. The magnitude of peak optical power and full width half maximum (FWHM) are predicted for various values of VCB. The collector base reverse bias voltage is varied from 0 V to 3 V. The peak optical pulse power is found to decrease with increasing reverse collector to base voltage. Full width half maximum is found to increase with increasing reverse collector to base voltage (VCB). The maximum peak optical power of 156.2 mW and minimum FWHM of 17.97 ps are predicted for the unbiased VCB at the base current amplitude of 128 mA. The optimum value of peak optical pulse power of 45.89 mW and full wave half maximum of 24.21 ps are obtained for the VCB value of 1.5 V at the base current amplitude of 96 mA.