Room-Temperature Fiber Tip Nanoscale Optomechanical Bolometer

Abstract

Nanomechanical bolometers have proven to be well suited to the analysis of light. However, conventional wafer-based devices have limited practical applications because they require special vacuum chambers, cryogenic temperatures, bulky space optical components, and/or complex circuitry. The present work developed a nanoscale optomechanical bolometer intended for photothermal sensing using an all-optical actuation and measurement approach. The proposed bolometer is compact and has an integrated all-optical-fiber structure based on fabricating a Fabry− Perot interferometer incorporating multilayer graphene at the fiber tip and packaged in a small vacuum-sealed tube. This microscale vacuum packaging doubled the signal-to-noise ratio compared with that in air. This miniature all-fiber nanoscale optomechanical bolometer also exhibited a high resolution with photothermal sensitivities of approximately 6.23 and 6.44 kHz/μW when using the second-order mode at room temperature and 0 °C, respectively. This design could be beneficial for applications outside specialized laboratories with uses in the fields of medicine, industrial manufacturing, nanoscience, and astronomy.

Nano-Optomechanical Resonators Based on Suspended Graphene for Thermal Stress Sensing

“…The other end of the HCF was well-cut with a fixed length of ~30 μm by using a standard fiber cleaver under a microscope system, so as to control the cavity length of the sensor precisely. Then, the MLG membrane was transferred to the end-facet of the HCF using a wet transfer technique reported in [ 25 ]. After the transfer, the device was dried in the air for several hours in order to evaporate the water molecule on the surface of the device and make the graphene membrane contact with the surface of the HCF.…”

“…Finally, the resonator was packaged in a sealed tube with a pressure of 5 × 10 −4 Pa. The micro-vacuum packaging technology reported in [ 25 ] was used to isolate air disturbance.…”

Carbon Nanotube-Based Uncooled Bolometers: Advances and Progress

“…Graphene BM on a (f) fiber-tip nano-optomechanical system resonator and (g) plasmonic photobolometric detector. [Panel (f) has been reproduced with permission from ref . Copyright 2022, American Chemical Society, Washington, DC.…”

“…Conventional microfabrication technologies, which include lithography and etching processes, are widely used for BM fabrication. , In recent years, however, innovative and advanced techniques, such as roll-to-roll nanoimprint lithography, vacuum filtration, , spray coating, and the implementation of optomechanical, photonic crystal cavity resonators, waveguides, ,, etc. are being introduced.…”

“…This can be achieved via a couple of ways, such as incorporating resonating (optically) components or clubbing additional absorption layers on the BM. Resonating structures, such as photonic crystal cavities, optomechanical cavities, or simple optical cavities utilizing Fabry–Perot resonances are used. ,, The second methodology to enhance optical absorption is via deposition of an additional layer of absorbing material (having higher absorption properties) on top of the BM element. Conventional techniques, such as thermal evaporation or CVD, are widely used for this purpose. , In addition to the above-discussed techniques, recently introduced techniques of spray coating and roll-to-roll nanoimprint lithography can be used for large-scale/throughput BMs. , Finally, umbrella-shaped double-layer microbridge structure (for increasing BM pixel fill factor), waveguide-integrated plasmonic designs, and engineering the supporting legs of the suspended BM films (I-type, U-type, meshed leg etc.)…”