Widely tunable laser
AssigneeJDS Uniphase Corporation
InventorHeino Bukkems
Life of this patent
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Abstract
A tunable laser having a tunable multi-mode interference (MMI) section is provided. The tunable laser also includes a gain section including an active waveguide, a phase section including a transparent waveguide, and a sampled grating section including a waveguide having a sampled Bragg grating written thereon or below. Each section is controlled via current injection. More specifically, the MMI section provides coarse tuning, the sampled grating section provides medium tuning, and the phase section provides fine tuning independence upon a current injected thereinto. The gain section provides optical gain. The configuration is relatively simple to control and easy to fabricate.
Claims21
A tunable laser comprising:
- a gain section including an active waveguide and a first current injector, the first current injector for injecting current into the active waveguide so as to provide optical gain;
- a phase section including a transparent waveguide and a second current injector, the second current injector for injecting current into the transparent waveguide so as to produce a refractive index change therein, the transparent waveguide optically coupled to the active waveguide;
- a multi-mode interference section including a multi-mode waveguide and a third current injector, the third current injector for injecting current into the multi-mode waveguide so as to produce local refractive index changes therein, the multi-mode waveguide optically coupled to the transparent waveguide;
- and
- a sampled grating section including another transparent waveguide and a fourth current injector, the other transparent waveguide coupled to a sampled Bragg grating, the fourth current injector for injecting current into the sampled Bragg grating so as to produce a refractive index change therein, the other transparent waveguide optically coupled to the multi-mode waveguide.
A tunable laser comprising:
- a substrate;
- an optical waveguide disposed on the substrate, the optical waveguide extending from a port on a front facet of the substrate towards an opposing end of the substrate;
- a sampled Bragg grating disposed near the optical waveguide proximate the opposing end, the sampled Bragg grating for reflecting predetermined wavelengths and forming a laser cavity with the front facet;
- and
- an active region disposed in the optical waveguide proximate the front facet, the active region for providing optical gain within the laser cavity,
- wherein the optical waveguide includes a multi-mode interference region disposed between the active region and the sampled Bragg grating, the multi-mode interference region for passing a range of wavelengths such that substantially only one of the predetermined wavelengths is output the port on the front facet, the range of wavelengths being variable in dependence upon an applied current to the multi-mode interference region.
A method of tuning a laser having a gain section, a phase section, a multi-mode interference section, and a sampled Bragg grating section, the method including the steps of:
- injecting current into a multi-mode interference waveguide disposed within the multi-mode interference section, the current injected in at least one predetermined location selected in dependence upon a desired tuning direction and with a magnitude selected in dependence upon a desired output wavelength of the laser.
Dependencies are inferred from the claim text.