Terahertz quantum cascade laser implementing a {hacek over (C)}erenkov difference-frequency generation scheme

US9711948B2 · kind B2 · utility

Assignee

• The Board of Regents of the University of Texas System · US

Inventors

• Mikhail A. Belkin · Austin, US
• Robert L. Adams · Kingston, US
• Markus-Christian Amann · Munich, DE
• Augustinas Vizbaras · Vilnius, LT

Key dates

• Filing date: Jul 24, 2013
• Grant date: Jul 18, 2017
• Expiry date: Sep 29, 2036

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S2302/02
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A terahertz source implementing a {hacek over (C)}erenkov difference-frequency generation scheme in a quantum cascade laser. The laser includes an undoped or semi-insulating InP substrate with an exit facet that is polished at an angle between 10° to 40°. The laser further includes a first waveguide cladding layer(s) in contact with an active layer (arranged as a multiple quantum well structure) and a current extraction layer on top of the substrate. Furthermore, the laser includes a second waveguide cladding layer(s) on top of the active layer, where the first and second waveguide cladding layers are disposed to form a waveguide structure by which terahertz radiation generated in the active layer is guided inside the laser. The terahertz radiation is emitted into the substrate at a {hacek over (C)}erenkov angle relative to a direction of the nonlinear polarization wave in the active layer, and once in the substrate, propagates towards the exit facet.