Spectroscopy using active diode laser stabilization by optical feedback

Patent · Tue May 11 04:00:00 EDT 1999

OSTI ID:1531823

Zare, Richard N.; Martin, Juergen; Paldus, Barbara A.

A cavity ring down spectroscopy (CRDS) system uses a free-running continuous wave (c.w.) diode laser stabilized by frequency-shifted optical feedback in the presence of strong reflections from a high-finesse Fabry-Perot resonator. The frequency-shifted feedback stabilization eliminates the need for tightly controlling the relative positions of the laser and resonator. Non-frequency-shifted feedback is used for linewidth broadening. An acousto-optic modulator placed between the diode laser output and the resonator input frequency-shifts light reflected by the resonator input, causing the laser to cycle in phase with a period equal to the inverse of the frequency-shift. The laser diode linewidth can be stabilized from several MHz for high resolution spectroscopy of species at low pressures, to several hundred MHz for lower resolution spectroscopy of species at atmospheric pressures.

• Research Organization: Leland Stanford Junior Univ., Stanford, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: FG03-92ER14304
• Assignee: The Board of Trustees of the Leland Stanford Junior University (Stanford, CA)
• Patent Number(s): 5,903,358
• Application Number: 08/949,241
• OSTI ID: 1531823
• Country of Publication: United States
• Language: English