Rapid temperature tuning of a 1.4-μm diode laser with application to high-pressure H2O absorption spectroscopy

Enhanced wavelength tuning of a distributed-feedback InGaAsP diode laser is demonstrated by use of rapid temperature cycling. The laser-active region is cycled from - 10 to + 50 degreesC (scanning the output from 1399 to 1403 mn) at kilohertz rates by pulsed heating with an auxiliary 532-nm laser. Such 4-mn scans represent a ten-fold increase in the wavelength-scanning range offered by standard current-tuning techniques and thus extend the capabilities of scan-wavelength sensors and systems. As an example application, we demonstrate absorption spectroscopy of H2O vapor at a pressure of 10 atm. (C) 2001 Optical Society of America.