Wavelength Tunable Semiconductor Laser Design And Manufacturing Process

Wavelength tunable laser is an important light source which has a popular application in these areas such as wavelength division multiplexing(WDM), reconfigurable optical add/drop multiplexing(ROADM), interferometry and spectroscopy and so on.In this article, two novel designs method of tunable lasers are proposed. First we will introduce the V-coupled cavity semiconductor laser. It has two waveguides offset which is different in length. By the vernier effect of the resonant wavelength of these two waveguides, the wavelength can be tuned effectively. This device can realize single mode selectivity by using one optical coupler to optimize the coupling coefficients of these two cavities. It also has a wide tuning range. Second, we will introduce a monolithically integrated mode-hop free tunable laser . It comprise an active waveguide, a wavelength dispersive diffraction grating with in an optical cavity, a slab waveguide region between the active waveguide and the grating, and a wavelength tuner region adjacent to the slab waveguide region having a predetermined shape and predetermined dimensions, said wavelength tuner region being sandwiched between a pair of electrodes for providing an electrical effect to vary the effective refractive index of the region and consequently to tune the wavelength of the grating filter while adjusting the optical cavity length simultaneously to achieve mode-hop free operation. This device structure can be applied to integrated tunable lasers with multiple wavelength bands and multiwavelength tunable laser arrays .In this article, the fabricating process of the V-coupled cavity semiconductor laser and the improvement of these processes such as photography, lift off, wet etching will be discussed.