Amplitude stabilization and active control of a terahertz quantum cascade laser with a graphene loaded split-ring-resonator array

We demonstrate the amplitude stabilization of a 2.85 THz quantum cascade laser with a graphene loaded split-ring-resonator array acting as an external amplitude modulator. The transmittance of the modulator can be actively changed by modifying the graphene conductivity via electrostatic back-gating. The modulator operates at room temperature and is capable of actively modulating the quantum cascade laser power level and thus stabilizing the power output via a proportional-integral-derivative feedback control loop. The stability was enhanced by more than 10 times through actively tuning the modulation. Furthermore, this approach can be used to externally control the laser power with a high level of stability.This work is supported by funding from the Engineering and Physical Sciences Research Council (Grant No. EP/P021859/1, HyperTerahertz–High precision terahertz spectroscopy and microscopy)

Active Frequency Modulation of Metamaterial/Graphene Optoelectronic Device Using Coupled Resonators

We present the continuous frequency modulation of a metamaterial resonance using selective damping of coupled plasmonic resonators with electrostatically gated graphene. A resonance frequency tuning range >150 GHz is achieved at 1.5 THz making this device suitable for use as an optoelectronic, tunable frequency modulator for THz frequencies

Amplitude Stabilization of a Terahertz Quantum Cascade Laser with an External Metamaterial Amplitude Modulator

Terahertz laser sources with stable power levels are requested for astronomical, communication and spectroscopic applications. Here we demonstrate the amplitude stabilization of a terahertz quantum cascade laser with a graphene loaded split-ring-resonator array. This integrated amplitude modulator operates at room temperature and is capable of actively modulating the quantum cascade laser power level and stabilizing the power output via a PID loop. The laser power fluctuation was reduced from 1.82% to 0.19% of the total power

Amplitude stabilization and active control of a terahertz quantum cascade laser with a graphene loaded split-ring-resonator array

We demonstrate the amplitude stabilization of a 2.85 THz quantum cascade laser with a graphene loaded split-ring-resonator array acting as an external amplitude modulator. The transmittance of the modulator can be actively changed by modifying the graphene conductivity via electrostatic back-gating. The modulator operates at room temperature and is capable of actively modulating the quantum cascade laser power level and thus stabilizing the power output via a proportional-integral-derivative feedback control loop. The stability was enhanced by more than 10 times through actively tuning the modulation. Furthermore, this approach can be used to externally control the laser power with a high level of stability

Optoelectronic control of an external cavity quantum cascade laser using a graphene loaded metamaterial array

We present the optoelectronic frequency and amplitude modulation of a terahertz quantum cascade laser, achieved by implementing a graphene loaded split ring resonator array into an external cavity feedback set-up. Amplitude modulation depths as high as 100% are achieved and the output frequency is lithographically and optoelectronically tuned

100 % amplitude modulation of an external cavity terahertz QCL using an optoelectronic chopper based on metamaterials and graphene

The continuous development of terahertz (THz) sources has opened up many potential applications in spectroscopy, imaging and communications. One popular THz source is the quantum cascade laser (QCL), which has many desirable properties including compactness and high output power with a narrow emission frequency. For such a source to be successfully integrated into a THz communication system, it is necessary to have control over the amplitude, frequency and phase. For wireless communication purposes, amplitude modulators must have a reasonable modulation depth and be capable of fast modulation speeds to take full advantage of the greater bandwidth opened up by using a THz carrier wave. To this purpose, we have developed optoelectronic split ring resonator (SRR) and graphene amplitude modulators which have been combined with a THz QCL thus realising an external cavity set-up which uses the SRR/graphene devices to efficiently modulate the light feedback into the laser cavity. The SRR/graphene device is lithographically designed to have maximum reflectivity at the QCL emission frequency (2.9 THz) and the graphene acts as a variable dampener, capable of electrically modulating the reflectivity. Similar SRR/graphene device architectures have been used previously for amplitude modulation by varying the reflection from a standard CW QCL output, achieving modulation speeds >100 MHz with a modulation depth limited to around 20

Research data supporting "Amplitude stabilization and active control of a terahertz quantum cascade laser with a graphene loaded split-ring-resonator array"

This directory contains the data relating to the figures in "Amplitude stabilization and active control of a terahertz quantum cascade laser with a graphene loaded split-ring-resonator array". Each opj file name describes which figure it is referring to. For any clarification or support, contact Binbin Wei at [email protected] work is supported by funding from the Engineering and Physical Sciences Research Council (Grant No. EP/P021859/1, HyperTerahertz–High precision terahertz spectroscopy and microscopy)

Optoelectronic control of an external cavity quantum cascade laser using a graphene loaded metamaterial array

We present the optoelectronic frequency and amplitude modulation of a terahertz quantum cascade laser, achieved by implementing a graphene loaded split ring resonator array into an external cavity feedback set-up. Amplitude modulation depths as high as 100% are achieved and the output frequency is lithographically and optoelectronically tuned

Research data supporting "Amplitude stabilization and active control of a terahertz quantum cascade laser with a graphene loaded split-ring-resonator array"

This directory contains the data relating to the figures in "Amplitude stabilization and active control of a terahertz quantum cascade laser with a graphene loaded split-ring-resonator array". Each opj file name describes which figure it is referring to. For any clarification or support, contact Binbin Wei at [email protected] or [email protected]