A NOVEL ANALYTICAL EXPRESSION OF SATURATION INTENSITY OF INGAASP TAPERED TRAVELING-WAVE SEMICONDUCTOR-LASER AMPLIFIER STRUCTURES

We have proposed a novel approximate analytical expression for saturat ion intensity for tapered traveling-wave semiconductor laser amplifier structures. The application of this analytical expression of saturati on intensity has been demonstrated by considering the effect of gain s aturation on polarization sensitivity of two tapered amplifier structu res, linear and exponential tapered amplifier structures. It is found that polarization sensitivity of the tapered amplifier structure is se veral decibels higher than that of passive tapered waveguides in unsat urated condition. Polarization sensitivity of the two tapered amplifie r structures has also been investigated in a highly saturated conditio n. The combined effects of mode conversion and gain saturation on fund amental TE gain have also been investigated using the proposed analyti cal expression for saturation intensity.