Fabrication and Characterization of Linear Terahertz Detector Arrays Based on Lithium Tantalate Crystal

Abstract

Two samples of 30-pixel linear terahertz detector arrays (TDAs) were fabricated based on lithium tantalate (LT) crystals. Pixel readout circuit (ROC) was designed to extract the weak current signal of TDAs. A test platform was established for performance evaluation of TDA+ROC components. By using a 2.52THz laser as radiation source, the test results reveal that average voltage responsivities of the components were larger than 7000V/W and non-uniformity no more than 2.1%. Average noise equivalent power (NEP) of one sample was measured to be 1.5×10 -9 W/Hz 1/2 , which is low enough and desirable for high performance THz detector.

Review of graphene for the generation, manipulation, and detection of electromagnetic fields from microwave to terahertz

“…While graphene-based detectors in the microwave and THz ranges already offer high photoresponsitivities of ∼700 V W −1 and NEP as little as 100 pW Hz −1/2 , which are comparable to commercially available room temperature THz detectors [253], these FOMs are still not as attractive as systems based on alternative materials. Their FOMs are at least one order of magnitude better with photoresponsitivities of up to 8600 V W −1 [256] and a NEP as little as 10 pW Hz −1/2 [259], see table 5. Nevertheless, many designs still lack an analysis of their response times, which is an important parameter for continuous readout in spectroscopy and imaging applications.…”

“…They offer wideband detection that is associated with the wideband characteristics of the metallic antennas used for the coupling of the EM fields into them. Moreover, they offer a great alternative to common pyroelectric [256], micro-bolometer [257], and silicon CMOS detectors [258][259][260]. Graphene-based detectors have been demonstrated to cover a wide frequency spectrum and are easy to fabricate due to their planar design.…”

Input Power and Effective Area in Terahertz Detector Measurement: A Review

“…However, a slow heating process in thermal detectors resulted in a tradeoff between responsivity and response time. Thermal detectors can be further subdivided into different approaches, namely pneumatic [36], bolometric [37], thermoelectric [38], and pyroelectric effects [39], with the independent material choices according to the selected approach. A pneumatic detector utilizes gas (e.g., xenon) in an enclosed chamber in which its volume is changing due to radiation heating that leads to displacement of the flexible membrane.…”

Electro-thermal and optical characterization of an uncooled suspended bolometer based on an epitaxial La0.7Sr0.3MnO3 film grown on CaTiO3/Si

“…It is desirable to have a NEP as low as possible, since a low NEP value corresponds to a lower noise floor and therefore a more sensitive detector. As shown in table 1, the lowest NEP values in the literature lie in the 10 −9 -10 −12 W • Hz −1/2 range for uncooled antenna-coupled detectors such as Golay cells [8], pyroelectric detectors [9], Schottky-barrier diodes [10], GaN high electron mobility transistors [11], metallic, VO 2 , amorphous Si (a-Si), or SiGe microbolometers [12][13][14][15].…”