Characteristics of a dual-wavelength semiconductor laser near 1550 nm

The implementation of a widely tunable, dual-wavelength semiconductor laser near 1550 nm is reported. The characteristics of its operation under different conditions of injection current and output feedback are discussed. Because the gain spectrum of this laser varied significantly with the injection current level, the signals of the two oscillating wavelengths interplay through the competition for the carriers. Generally, the feedback of the signal of one wavelength enhanced its own output power and suppressed the other unless the gain of the former is significantly lower than the later.