Title :
Packing techniques to increase wavelength tuning of distributed feedback lasers
Author :
Vermaak, J.S. ; Ranallo, M.J. ; Martinelli, R.U. ; Menna, R.J. ; Connolly, J.C.
Author_Institution :
Sensors Unlimited Inc., Princeton, NJ, USA
Abstract :
Summary form only given. Distributed feedback (DFB) diode lasers are used as sources in laser absorption spectrometers for trace gas analysis. Many molecules, including common environmental pollutants and toxic chemicals, have absorption bands between 760 nm and 2004 nm. These bands are strong enough to allow detection at or below the parts-per-million (ppm) level. In order to sweep through an absorption peak a wavelength tuning range of over one wave number is typically required. In FM spectroscopy the wavelength of the laser is tuned with temperature close to the absorption peak. A low-frequency (ranging from a few Hz to 1 kHz) saw tooth current ramp is then applied to the diode laser that repetitively sweeps its emission frequency across the absorption peak. One needs as high as possible a current tuning rate for as small as possible a current change to minimize power changes and non-linearity.
Keywords :
distributed feedback lasers; frequency modulation; infrared spectroscopy; laser beam applications; laser feedback; laser tuning; light sources; modulation spectroscopy; optical modulation; semiconductor device packaging; semiconductor lasers; spectrochemical analysis; 760 to 2004 nm; FM spectroscopy; absorption bands; absorption peak; current change; current tuning rate; detection; diode laser; distributed feedback diode lasers; distributed feedback lasers; emission frequency; environmental pollutants; laser absorption spectrometers; low-frequency saw tooth current ramp; nonlinearity; packing techniques; parts-per-million level; power changes; toxic chemicals; trace gas analysis; wavelength tuning; wavelength tuning range; Absorption; Chemical lasers; Diode lasers; Distributed feedback devices; Gas lasers; Laser feedback; Laser tuning; Pollution; Spectroscopy; Toxic chemicals;
Conference_Titel :
Lasers and Electro-Optics, 2000. (CLEO 2000). Conference on
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
1-55752-634-6
DOI :
10.1109/CLEO.2000.906859