Abstract-A Low-Cost Terahertz Camera

François Blanchard,  Joel Edouard Nkeck, Dominique Matte, Riad Nechache, David G. Cooke,

https://www.mdpi.com/2076-3417/9/12/2531

Cost effective imaging is required for a wide range of scientific and engineering applications. For electromagnetic waves in the terahertz (THz) frequency range, a key missing element that has prevented widespread applications in this spectral range is an inexpensive and efficient imaging device. In recent years, vanadium oxide based thermal sensors have rapidly entered the market for night vision capability. At the same time, sensors based on this technology have been applied to the THz domain, but with two orders of magnitude larger pricing range. Here we show that, with a simple modification, a commercially available thermal imaging camera can function as a THz imaging device. By comparing a commercially available THz camera and this low-cost device, we identify the main sensitivity difference is not attributed to anything intrinsic to the devices, but rather to the analog-to-digital converter and dynamic background subtraction capability. This demonstration of a low-cost THz camera may aid in the rapid development of affordable THz imaging solutions for industrial and scientific applications

Abstract-Active phase control of terahertz pulses using a dynamic waveguide

Lauren Gingras, Wei Cui, Aidan W. Schiff-Kearn, Jean-Michel Ménard, and David G. Cooke

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-11-13876

Control over the spectral phase of a light pulse is a fundamental step toward arbitrary signal generation in a spectral band. For the terahertz spectral regime, pulse shaping holds the key for applications ranging from ultra-high speed wireless data transmission to quantum control with shaped fields. In this work, we demonstrate a technique for all-optical and reconfigurable control of the spectral phase of a light pulse in the important terahertz (THz) band. The technique is based on interaction of a guided THz pulse with patterned photoexcited regions within a uniform silicon-filled parallel-plate waveguide. We use this platform to demonstrate broadband and tunable positive and negative chirp of a THz pulse, as well as control of the pulse carrier envelope phase.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Abstract-Dynamic creation of a light-induced terahertz guided-wave resonator

Lauren Gingras, François Blanchard, Marcel Georgin, and David G. Cooke
https://www.osapublishing.org/oe/abstract.cfm?uri=oe-24-3-2496

We demonstrate a dynamic light-induced resonator for terahertz (THz) frequency light created on ultrashort time scales inside a planar waveguide. The resonator is created by patterned femtosecond photoexcitation of a one-dimensional array of photoconductive regions inside a silicon-filled parallel plate waveguide. The metal-dielectric photonic crystal is created on a 2 ps time scale, ten times faster than the 20 ps transit time of the THz light through the array. The resonance reveals itself through narrowband THz transmission enhancement with accompanying phase modulation producing an induced group delay of up to 10.8 ps near resonance.

© 2016 Optical Society of America

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Abstract-Temporal and spectral shaping of broadband terahertz pulses in a photoexcited semiconductor

Mostafa Shalaby^1,2,a), Marco Peccianti³, David G. Cooke⁴, Christoph P. Hauri^2,5 and Roberto Morandotti
http://scitation.aip.org/content/aip/journal/apl/106/5/10.1063/1.4907635
a) most.shalaby@gmail.com and morandotti@emt.inrs.ca
Appl. Phys. Lett. 106, 051110 (2015); http://dx.doi.org/10.1063/1.4907635

Transmission through a photoexcited semiconductor is used to temporally and spectrally shape a terahertz (THz) pulse. By adjusting the optical pump-THz probe delay, we experimentally introduce a polar asymmetry in the pulse profile as large as 92%. To shape the spectrum, we apply the same technique after strongly chirping the terahertz pulse. This leads to significant reshaping of the spectrum resulting in a 52% upshift of its median value. The pulse shaping techniques introduced here are of particular importance for temporal and spectralshape-sensitive THz nonlinear experiments.