Title :
Using diffractive optics for tuning custom-designed broadband diode lasers
Author :
Woodworth, S.C. ; Cassidy, D.T. ; Hamp, M.J.
Author_Institution :
Dept. of Eng. Phys., McMaster Univ., Hamilton, Ont., Canada
Abstract :
Summary form only given. Asymmetric multiple-quantum-well (AMQW) InGaAsP lasers have been designed and fabricated which exhibit broad gain profiles and a significantly increased tuning range due to equal contributions to the gain from the various QWs in the active region. The device structure is a Fabry-Perot (FP) ridge waveguide with 3 /spl mu/m ridge width, and no facet coatings. The active region consists of two 50 /spl Aring/ and two 100 /spl Aring/ QWs separated by 30 /spl Aring/ barriers. A diffractive optical element (DOE) was used in an external cavity to tune the output wavelength of the AMQW lasers. The DOE was designed to replace the combination of a grating and lens in the Littrow configuration and is a reflective Fresnel phase element which provides a strong wavelength dependent focal length. This tunable laser system was used experimentally as a broadband absorption spectrometer. Sensitive detection of trace-gas spectra was performed.
Keywords :
III-V semiconductors; diffractive optical elements; gallium arsenide; indium compounds; laser cavity resonators; laser tuning; quantum well lasers; spectroscopic light sources; waveguide lasers; 100 A; 3 micron; 30 A; 50 A; DOE; Fabry-Perot ridge waveguide; InGaAsP; asymmetric multiple-quantum-well InGaAsP lasers; broad gain profiles; broadband absorption spectrometer; custom-designed broadband diode lasers; diffractive optical element; diffractive optics; external cavity; reflective Fresnel phase element; strong wavelength dependent focal length; trace-gas spectra; tuning; Diode lasers; Laser tuning; Optical design; Optical diffraction; Optical sensors; Optical tuning; Optical waveguides; Quantum well devices; US Department of Energy; Waveguide lasers;
Conference_Titel :
Lasers and Electro-Optics, 2002. CLEO '02. Technical Digest. Summaries of Papers Presented at the
Conference_Location :
Long Beach, CA, USA
Print_ISBN :
1-55752-706-7
DOI :
10.1109/CLEO.2002.1033645