Temporal wavelength multiplexing of quantum cascade laser

Abstract

A quantum cascade (QC) laser is presented that is both temporally and wavelength multiplexed, i.e. it emits two widely different wavelengths at two alternate time slots. A bidirectional and multi-wavelength QC laser source that emits at 10.8m wavelength for a positive polarity current and 8.6m for a negative polarity current was used. A diode based adder circuit was designed to drive the QC laser such that it added two opposite polarity current pulses with a variable time delay. Application of two polarity 100ns pulse width current pulses at 80kHz with time delays of 0.5 to 2.5s resulted in a versatile time and wavelength multiplexed QC laser. © 2009 The Institution of Engineering and Technology.