Novel transverse twin-guide tunable semiconductor laser

Single mode laser diodes with an electrically tunable wavelength are indispensable components of advanced optical communication. Wavelength division multiplexing and coherent multichannel applications rely heavily on the ability to tune the laser wavelength electronically. Thus, the tuning range should extend over several hundred GHz and the tuning behavior should be continuous. Sice mode changes are excluded in the continuous tuning mode, the wavelength setting can be performed by relatively simple control circuitry. The quasi-continuous tuning mode, on the other hand, is less attractive in practice because of the complicated wavelength control scheme, even though the total tuning range may be larger.