title: Active Wavelength Control of an External Cavity Quantum Cascade Laser.
abstract: We present an active wavelength control system for grating-based external cavity lasers that increases the accuracy of predicting the lasing wavelength based on the grating equation and significantly improves scan-to-scan wavelength/frequency repeatability. The ultimate 3σ precision of a frequency scan is determined by the scan-to-scan repeatability of 0.042 cm-1. Since this control method can be applied to any external cavity laser with little to no modification, such a precision provides an excellent opportunity for spectroscopic applications that target molecular absorption lines at standard atmospheric conditions.
authors.affiliation: Electrical Engineering Dept., Princeton University, Princeton, NJ 08544 USA.
authors.forename: Tracy
authors.initials: T
authors.lastname: Tsai
authors.forename: Gerard
authors.initials: G
authors.lastname: Wysocki