Laser device

Abstract

A laser comprising first and second feedback elements defining a laser cavity, and a gain medium within the laser cavity, the gain medium having first and second facets (5, 6) and an optical waveguide (8) for guiding optical radiation between said first and second facets, wherein the second feedback element is wavelength selective, and the optical waveguide (8) is configured to direct optical radiation at an angle theta to the normal of the second facet (6).

Description

technical field [0001] The present invention relates to a laser. Background technique [0002] In optical telecommunication networks, for example, lasers with narrow linewidth outputs are required. Such lasers can be used, for example, in wavelength-division multiplexing systems where densely packed different wavelengths are utilized to transmit different channels, or in high-bit-rate systems where narrow linewidth sources are required to avoid dispersion effects . Distributed feedback (DFB) semiconductor lasers with diffraction gratings in semiconductor gain materials have been utilized for these applications. A disadvantage of these distributed feedback lasers is that, due to the temperature-dependent refractive index of the semiconductor material, its output wavelength varies with its temperature. This usually requires the use of a temperature controller and associated electronics to stabilize the temperature of the profile feedback laser and thus its output wavelength...

AI Technical Summary

Problems solved by technology

The disadvantage of these distributed feedback lasers is that the output wavelength varies with the temperature of the semiconductor material due to the temperature-dependent refractive index of the semiconductor material

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