Performance evaluation of free space optical link driven by gain switched temperature dependent quantum cascade lasers

Abstract

Temperature dependent terahertz frequency quantum cascade lasers (QCLs) offer huge potential in a large number of new applications. Reduced rate equations are used for better understanding of their behavior and to predict the optical output power under changing current drive and chip temperature. This letter reports the complete end-to-end free space optical (FSO) link driven by a gain switched temperature dependent QCL as transmitter. The device used in the FSO link consists of 90 periods of injector and active regions, emitting light at 116 µm. The device is driven by various electrical inputs such as square, haversine and tangential hyperbolic pulses. The short pulses generated by gain switching travel 1500 m to reach the quantum well infrared photodetector operating in the same wavelength as the source. The performance parameters; namely signal-to-noise ratio (SNR), bit error rate (BER) and capacity are computed for the various input signals. Under the minimum full width half maximum condition, haversine input provides a better performance providing a BER of 7.8 × 10−5, with a peak SNR of 14.56 dB and a capacity of 4.89 bps Hz−1 at a cold finger temperature of 45 K. When peak power is the criterion, tangential hyperbolic input performs well with a minimum BER of 7.66 × 10−9, a peak SNR of 18.06 dB and a capacity of 6.02 bps Hz−1 at a cold finger temperature of 45 K.

Optical Hybrid Network Structure Based on Cloud Computing and Big Data Technology

“…The link with a long response time and congestion becomes unblocked. In addition, the link can also carry part of the data of adjacent links, realizing the common transmission of data in the optical and electrical domains, reducing the data backlog of nearby links and making full use of the optical link [13].…”

High-power quantum cascade lasers for 8 μm spectral range

“…Compactness and efficiency of QCLs determine the variety of their applications in medicine [1], environmental monitoring [2,3] and monitoring of technological processes [4,5,6]. Developments are also underway for the use of QCLs in biomedicine [7,8], defense and security [6,9], and secure free-space optical communication, primarily in the mid-IR atmospheric transparency windows [10,11,12].…”

Numerical Investigation on the Temperature dependent Impedance Characteristics of Far-Infrared Quantum Cascade Lasers

“…Gain switching based applications of QCL are well documented in [5][6][7]. Free Spaced Optics based applications of QCL are simulated and analyzed in [8][9][10][11][12]. Impedance characteristics have been well documented for QCLs and semiconductor laser diodes [8,13].…”