Abstract: A single-wavelength distributed feedback (DFB) laser structure is provided. The laser structure having two sections includes an active-material layer for generating a laser having a wavelength in a specific range, two cladding layers respectively covering an upper and a bottom sides of the active-material layer for forming a waveguide structure, a phase shift layer having a specific thickness for controlling a difference between Bragg wavelengths of the two sections, a wet-etching stop layer positioned between the active-material layer and the phase shift layer, and a grating layer having a specific period for determining an illuminating wavelength, wherein a difference between the two sections is an existence of the phase shift layer thereon, and the existence of the phase shift layer causes a difference of the effective refractive indices between the two sections so as to generate a fixed difference between Bragg wavelengths of the two sections.

Abstract: A single-wavelength distributed feedback (DFB) laser structure is provided. The laser structure having two sections includes an active-material layer for generating a laser having a wavelength in a specific range, two cladding layers respectively covering an upper and a bottom sides of the active-material layer for forming a waveguide structure, a phase shift layer having a specific thickness for controlling a difference between Bragg wavelengths of the two sections, a wet-etching stop layer positioned between the active-material layer and the phase shift layer, and a grating layer having a specific period for determining an illuminating wavelength, wherein a difference between the two sections is an existence of the phase shift layer thereon, and the existence of the phase shift layer causes a difference of the effective refractive indices between the two sections so as to generate a fixed difference between Bragg wavelengths of the two sections.

Abstract: This invention demonstrates an adjustable monolithic multi-wavelength laser diode array formed on a substrate a plurality of diode lasers, each has an active section and two mirrors with similar multiple reflectivity peaks. A phase control section can also be included in each laser for fine tuning of the laser wavelength. Each laser in the laser array can emit light at the same wavelength or can be easily tuned to form an array with multiple wavelengths. To serve as an application example of this invention, sampled grating DBR lasers are designed to form a laser array with adjustable multi-wavelength outputs. By varying from laser to laser the sampling periods of the sampled gratings in each laser, a uniformly-spaced multi-wavelength laser array can be achieved with a simple tuning mechanism. The lasers can also emit light at the same wavelength or be tuned to other wavelengths by tuning the sampled grating mirrors.