Light-emitting device having III-V semiconductor gain section coupled to whistle-geometry tunable filter

A wavelength tunable semiconductor laser comprising a laser gain section (510,610,710), the laser gain section being optically coupled to an optical waveguide (520,620,720) having a first end (521,621,721) and a second end (522,622,722), a first passive microring resonator (530,630,730) being arranged between said first end and said laser gain section, characterized in that:

• the first passive microring resonator is extended by a first optical waveguide branch (540,640,740) tangentially connected thereto according to a whistle geometry, the first optical waveguide branch being provided with a first highly reflective broadband mirror (541,641,741) at its free end,
• the optical waveguide is provided with a first mirror (523,623,723) at its first end and with a second mirror (524,624,724) at its second end;
• the first microring resonator is evanescently coupled with the optical waveguide on a first side of the laser gain section to provide an optical feedback to the laser gain section;
• the first and second passive microring resonators, including the first and second optical waveguide branches of said optical waveguide, constitute a pattern of silicon on a SiO2 layer coating a Si substrate;
• and
• the wavelength tunable semiconductor laser is implemented according to a III-V/Si technology.

A wavelength tunable semiconductor laser comprising a laser gain section (510,610,710), the laser gain section being optically coupled to an optical waveguide (520,620,720) having a first end (521,621,721) and a second end (522,622,722), a first passive microring resonator (530,630,730) being arranged between said first end and said laser gain section, characterized in that:

• the first passive microring resonator is extended by a first optical waveguide branch (540,640,740) tangentially connected thereto according to a whistle geometry, the first optical waveguide branch being provided with a first highly reflective broadband mirror (541,641,741) at its free end,
• the optical waveguide is provided with a first mirror (523,623,723) at its first end and with a second mirror (524,624,724) at its second end;
• the first microring resonator is evanescently coupled with the optical waveguide on a first side of the laser gain section to provide an optical feedback to the laser gain section;
• the first passive microring resonator is provided with a controllable heater (580,680,780);
• and
• an intermediate passive microring resonator (760) arranged between the first passive microring resonator and the optical waveguide, said intermediate passive microring resonator being evanescently coupled with the first passive microring resonator and the optical waveguide.