Wavelength switching in multi-cavity laser diodes

We study experimentally and numerically electrical and optical methods to switch the lasing wavelength in a linear multi-cavity laser. The electrical method uses radio frequency modulation of the gain region to modify effective optical loss at a well-defined wavelength. The optical method uses injection of lasing light to modify effective photon lifetime at the injection wave-length. Short transient switching times corresponding to less than two photon-cavity round-trips are observed using both methods. However, this occurs for small spectral separation between lasing wavelengths, a less effective mode suppression ratio, and an asymmetry in switching time to and from a given lasing wavelength. The maximum wavelength switching speed is determined by the net optical gain and the initial number of photons in each cavity mode. © 1998 American Institute of Physics. @S0021-8979~98!02916-8#