Patent ID: 8295320
Filing Date: 2012-10-23
Classification: H01S

Abstract:
1. An external cavity laser (ECL) device with narrow linewidth and low noise, comprising: a planar lightwave circuit (PLC) device with a planar Bragg grating (PBG) integrated onto a rectangular waveguide, wherein the PLC device has anti-reflection coatings (ARC) on an input facet and an output facet, and wherein the waveguide is designed to be selective of a single polarization; and a gain chip having a high-reflection coating (HRC) on a back facet and an ARC on a front facet, wherein the front facet of the gain chip is butt-coupled to the input facet of the PLC device, wherein an operating wavelength of the ECL is aligned to a longer wavelength negative red slope of a reflectivity spectrum of the PBG, such that both the negative red slope and a group delay have respective high values at the operating wavelength region, thereby achieving low phase noise for the ECL; wherein the gain chip has a low differential gain to suppress side modes.