Semi-integrated designs for external cavity tunable lasers

A tunable laser, comprising:

• a base;
• an integrated structure operatively coupled to the base, having a front facet and a substantially non-reflective rear facet optically coupled via a waveguide passing therethrough, the integrated structure further including;
• a gain section to emit a plurality of photons in response to a first electrical input, having a facet defining the rear facet of the integrated structure;
• a phase control section disposed adjacent to the gain section, to modulate an optical path length of a portion of the waveguide passing through the control section in response to a second electrical input;
• the phase control section having;
• a partially-reflective mirror optically coupled to the portion of the waveguide passing through the phase control section, the partially-reflective mirror having a reflectivity of approximately 2-10 percent;
• a modulator section disposed adjacent to the phase control section, to modulate an optical output passing through a portion of the waveguide passing through the modulator section in response to a third electrical input, and having a facet defining the front facet of the integrated structure;
• a reflective element operatively coupled to the base and disposed opposite the substantially non-reflective rear facet to form an external cavity;
• and
• a tunable filter including at least one optical element operatively coupled to the base and disposed in the external cavity.

A telecommunication switch comprising;

• a plurality of fiber line cards, each including,
• a multi-stage multiplexer/demultiplexer;
• a circulator bank, comprising a plurality of circulators operatively coupled to the multi-stage multiplexer/demultiplexer;
• a receiver bank, comprising a plurality of receivers operatively coupled to respective circulators;
• and
• a transmitter bank, comprising a plurality of transmitters operatively coupled to respective circulators, each transmitter comprising at tunable external cavity diode laser (ECDL), including;
• a base;
• an integrated structure operatively coupled to the base, having a front facet and a substantially non-reflective rear facet optically coupled via a waveguide passing therethrough, the integrated structure further including:
• a gain section to emit a plurality of photons in response to a first electrical input, having a facet defining the rear facet of the integrated structure;
• a phase control section disposed adjacent to the gain section, to modulate an optical path length of a portion of the waveguide passing through the control section in response to a second electrical input;
• a modulator section disposed adjacent to the phase control section, to modulate an optical output passing through a portion of the waveguide passing through the modulator section in response to a third electrical input, having a facet defining the front facet of the integrated structure;
• and
• a partially-reflective mirror disposed between the phase control section and the modulator section, the partially-reflective mirror having a reflectivity of approximately 2-10 percent;
• a reflective element, operatively coupled to the base and disposed opposite the substantially non-reflective rear facet to form an external cavity;
• and
• a tunable filter including at least one optical element operatively coupled to the base and disposed in the external cavity.