Static and Dynamic Characteristics of Digital Wavelength Switching in V-Coupled-Cavity Semiconductor Laser

The static and dynamic characteristics of digital wavelength switching in a novel V-coupled-cavity semiconductor laser is investigated. In contrast to previously investigated Y-laser, the V-shaped coupler can realize not only an optimum coupling coefficient but also a ¿-phase difference between the cross-coupling and self-coupling coefficients, which results in a high single-mode selectivity. It is shown that while switching to an optimal current value results in the maximal output power and maximal side-mode suppression ratio (SMSR), the digitally wavelength switchable laser has a good tolerance on the accuracy of the switching current. For a current deviation corresponding to ±25% of the channel spacing, the SMSR only degrades by about 5.2 dB, while the wavelength varies by only ±0.01 nm from the set value for the case of 0.8 nm channel spacing. The dynamic properties including the switching transients and switching delay are also investigated and discussed.