2015-05-042015-05-042007-07-24Kosterev, Anatoliy A. and Tittel, Frank K., "Frequency scanning pulsed laser having synchronously set subthreshold current." Patent US7248611B2. issued 2007-07-24. Retrieved from https://hdl.handle.net/1911/79945.https://hdl.handle.net/1911/79945The present invention provides methods and apparatus for flexible and reproducible control of quantum cascade laser frequency scans having short (nanosecond) pulse excitations. In accordance with a preferred embodiment of the invention, a method of digital frequency control for pulsed quantum cascade lasers includes digitally synthesizing a sub-threshold current, converting the sub-threshold current to analog form, and generating laser pulses. Preferably, the sub-threshold current is synchronized to the laser pulses.9 ppengUtility patentUS7248611B2