US 6,480,513 B1 · Tunable external cavity laser

Abstract

A tunable laser system comprises an externalcavity laser diode in combination with an optically coupled waveguide having a Bragg grating formed therein. The laser diode provides a gain medium characterized by a first band of wavelengths. A portion of the fiber and the grating help define an external resonant cavity. The grating limits the wavelengths exiting the external cavity to a second band that is typically much narrower than the first band. The grating region of the waveguide is thermally coupled to a heating element having an associated temperature controller for controllably varying the temperature of the grating region and thus changing the optical pitch of the grating and thus the second band. The grating region of the waveguide can alternatively, or additionally, be subjected to acoustic energy to change the optical pitch of the grating.

Claims24

Dependent claims

A tunable optical source comprising:

a laser device configured to emit light over a first band of wavelengths;
a waveguide positioned to receive light emitted by said laser device;
a grating formed within and extending along at least a portion of said waveguide;
a portion of said waveguide and said grating at least partially defining an external cavity with said grating limiting light exiting said external cavity in a particular direction to a second band of wavelengths that is narrower than, and contained within the first band of wavelengths;
said second band of wavelengths depending on a set of one or more properties of said grating and said waveguide;
and
a mechanism for controllably changing at least one property in said set so as to change the location of said second band of wavelengths in accordance with said change in said at least one property.

4 more elements

A tunable laser array having a plurality of laser assemblies, each assembly comprising:

a laser device configured to emit light over a respective first band of wavelengths;
a waveguide positioned to receive light emitted by that assembly's laser device;
a grating extending along that assembly's waveguide;
a portion of that assembly's waveguide and that assembly's grating at least partially defining an external cavity with that assembly's grating limiting light exiting that assembly's external cavity in a particular direction to a second band of wavelengths that is smaller than, and contained within that assembly's first band of wavelengths;
that assembly's second band of wavelengths depending on a set of one or more properties of that assembly's grating and waveguide;
and
a mechanism for controllably changing at least one property in that assembly's set so as to change the location of that assembly's second band of wavelengths in accordance with said change in said at least one property to provide a wavelength tuning range for that assembly.

4 more elements

Dependencies are inferred from the claim text.

Tunable external cavity laser

Life of this patent

Tunable external cavity laser

Life of this patent

Abstract

Claims24