Patent ID: 8238388
Filing Date: 2012-08-07
Classification: H01S

Abstract:
1. A tunable laser device for producing light of respective selectable wavelengths, the tunable laser device comprising: a first ridge waveguide extending between a first proximal end and a first distal end, and having a first ridge defining a first light guiding region extending in a longitudinal direction between the first proximal end and the first distal end thereof, a second ridge waveguide extending between a second proximal end and a second distal end, and having a second ridge defining a second light guiding region extending in a longitudinal direction between the second proximal end and the second distal end thereof, the first and second light guiding regions communicating through the first and second proximal ends thereof, and emitting light of the selectable wavelength through one of the first and second distal ends, a plurality of first refractive index altering means equi-spaced apart along the first ridge of the first waveguide for altering the refractive index of the first light guiding region at spaced apart locations therein to produce a first mirror loss spectrum with minimum peak values at respective first wavelength values, the spacing d where N λ is the centre wavelength of the range of wavelengths of light over which the laser device is to be tunable, and n a plurality of second refractive index altering means equi-spaced apart along the second ridge of the second waveguide for altering the refractive index of the second light guiding region at spaced apart locations therein to produce a second mirror loss spectrum with minimum peak values at respective second wavelength values, the spacing d where N λ is the centre wavelength of the range of wavelengths of light over which the laser device is to be tunable, and n a refractive index varying means for selectively varying the refractive index of at least the first light guiding region for in turn varying the first mirror loss spectrum until one of the first wavelength values is similar to one of the second wavelength values to produce light of a selected one of the wavelengths.