Patent ID: 8885677

Claim:
A semiconductor external cavity laser (ECL) with narrow line width, low noise and wide bandwidth uniform frequency modulation capabilities in both magnitude and phase, the semiconductor ECL comprising: a silica-on-silicon planar light wave circuit (PLC) comprising a semiconductor laser waveguide with embedded Bragg grating; a semiconductor gain chip butt coupled to the PLC, and a lithium niobate phase tuning element is optically coupled to the semiconductor gain chip; wherein anti-reflection (AR) coating cover a front facet of the lithium niobate phase tuning element, a front facet of the semiconductor gain chip that butt coupled to the PLC, and a front facet of the PLC; and high-reflection (HR) coating covers a back facet of the lithium niobate phase tuning element defining a back facet of an external cavity of the semiconductor ECL; wherein an alternating-current (AC)-voltage applied to electrodes of the lithium niobate phase tuning element generates an electric field, and the semiconductor gain chip acting as a polarizer allows to propagate in the external cavity only a transverse electric (TE) mode aligned perpendicular to a direction of the electric field in the lithium niobate phase tuning element; where a length of the lithium niobate phase tuning element is tailored to lasing characteristics of the PLC to achieve uniform frequency modulation response in phase and magnitude.