Broadly tunable single-mode quantum cascade laser sources and sensors

US7826509B2 · kind B2 · utility

Assignee

• President and Fellows of Harvard College · US

Inventors

• Mikhail A. Belkin · Austin, US
• Benjamin G. Lee · Ridgefield, US
• Ross M. Audet · Menlo Park, US
• James B. MacArthur · Kitchener, CA
• Laurent Diehl · Cambridge, US
• Christian Pflugl · Cambridge, US
• Federico Capasso · Westfield, US

Key dates

• Filing date: Dec 15, 2006
• Grant date: Nov 2, 2010
• Expiry date: Feb 19, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01S5/4087
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A broadly tunable single-mode infrared laser source based on semiconductor lasers. The laser source has two parts: an array of closely-spaced DFB QCLs (or other semiconductor lasers) and a controller that can switch each of the individual lasers in the array on and off, set current for each of the lasers and, and control the temperature of the lasers in the array. The device can be used in portable broadband sensors to simultaneously detect a large number of compounds including chemical and biological agents. A microelectronic controller is combined with an array of individually-addressed DFB QCLs with slightly different DFB grating periods fabricated on the same broadband (or multiple wavelengths) QCL material. This allows building a compact source providing narrow-line broadly-tunable coherent radiation in the Infrared or Terahertz spectral range (as well as in the Ultraviolet and Visible spectral ranges, using semiconductor lasers with different active region design). The performance (tuning range, line width, power level) is comparable to that of external grating tunable semiconductor lasers, but the proposed design is much smaller and much easier to manufacture.