Showing posts with label James Grant. Show all posts
Showing posts with label James Grant. Show all posts

Friday, November 2, 2018

Abstract-Unity Integration of Grating Slot Waveguide and Microfluid for Terahertz Sensing



Li Liang, Xin Hu, Long Wen, Yuhuan Zhu, Xianguang Yang, Jun Zhou, Yaxin Zhang,Ivonne Escorcia Carranza,  James Grant,  Chunping Jiang, David R. S. Cumming,  Baojun Li,  Qin Chen,

https://onlinelibrary.wiley.com/doi/abs/10.1002/lpor.201800078

Refractive index sensing is attracting extensive interest. Limited by the weak light–matter interaction and the broad bandwidth of resonance, the figure of merit (FoM) of terahertz (THz) sensors is much lower than their counterparts in visible and infrared regions. Here, these two issues are addressed by incorporating a microfluidic channel as a slot layer into a grating slot waveguide (GSW), where guided‐mode resonance results in a narrowband resonant peak and the sensitivity increases remarkably due to the greatly concentrated electromagnetic fields in the slot layer. Both reflective and transmissive sensors are developed with the calculated quality (Q) factors two orders of magnitude larger than metamaterial and plasmonic sensors, and the sensitivities one order of magnitude larger than grating waveguide sensors, contributing to a record high FoM of 692. The measured results match well with the simulations considering the fabrication errors, where the degeneration of narrowband transmission peaks in experiments is attributed to the error of the microfluidic channel height and the divergence of the incident beam. The proposed unity‐integrating configuration with simultaneous optimizations of the resonance mechanism, and the spatial overlap between the sensing field and the analytes shows the potential for high sensitivity bio and chemo sensing.

Saturday, July 9, 2016

Abstract-Uncooled CMOS terahertz imager using a metamaterial absorber and pn diode













We demonstrate a low-cost uncooled terahertz (THz) imager fabricated in a standard 180 nm CMOS process. The imager is composed of a broadband THz metamaterial absorber coupled with a diode microbolometer sensor where the pn junction is used as a temperature sensitive device. The metamaterial absorber array is integrated in the top metallic layers of a six metal layer process allowing for complete monolithic integration of the metamaterial absorber and sensor. We demonstrate the capability of the detector for stand-off imaging applications by using it to form transmission and reflection images of a metallic object hidden in a manila envelope.
© 2016 Optical Society of America
Full Article  |  PDF Article

Friday, February 12, 2016

James Grant author of Multi-spectral materials: hybridisation of optical plasmonic filters, a mid infrared metamaterial absorber and a terahertz metamaterial absorber, provides some further information

My Note: I got an email from Dr. James Grant who provided me, with additional information concerning the background of the last Abstract I just posted, which I wanted to share with readers. Thank you Dr. Grant for sharing this, and best of luck in creating the Supercamera!
___________
Hi Randy,

I follow your blog – it’s an excellent way to easily keep up to date with relevant THz commercialization and activity....

In (this paper) we co-axially integrate a THz and MIR Metamaterial absorber with visible plasmonic filters. Such a component could be combined with suitable sensors (such as micro-bolometers and pn photodiodes) into CMOS technology to realise a focal plane array capable of forming a visible, IR and THz images of a scene. Indeed this is the crux of the grant that we I am currently working on:


Best wishes,

James

Dr. James Paul Grant
Postdoctoral Research Fellow
Microsystems Technology Group
Rankine Building, Room 512C, School of Engineering
University of Glasgow
Glasgow
Scotland
G12 8LS

(The link above,  takes readers to a 2013 grant entitiled: 
 "Triple wavelength superspectral camera focal-plane array (SUPERCAMERA)"

Optical imaging is perhaps the single most important sensor modality in use today. Its use is widespread in consumer, medical, commercial and defence technologies. The most striking development of the last 20 years has been the emergence of digital imaging using complementary metal oxide semiconductor (CMOS) technology. Because CMOS is scalable, camera technology has benefited from Moore's law reduction in transistor size so that it is now possible to buy cameras with more than 10 MegaPixels for £50. The same benefits are beginning to emerge in other imaging markets - most notably in infrared imaging where 64x64 pixel thermal cameras can be bought for under £1000. Far infrared (FIR), or terahertz, imaging is now emerging as a vital modality with application to biomedical and security imaging, but early imaging arrays are still only few pixel research ideas and prototypes that we are currently investigating. 

There has been no attempt to integrate the three different wavelength sensors coaxially on to the same chip. Sensor fusion is already widespread whereby image data from traditional visible and mid infrared (MIR) sensors is overlaid to provide a more revealing and data rich visualisation. Image fusion permits discrepancies to be identified and comparative processing to be performed. Our aim is to create a "superspectral" imaging chip. By superspectral we mean detection in widely different bands, as opposed to the discrimination of many wavelengths inside a band - e.g. red, green and blue in the visible band. We will use "More than Moore" microelectronic technology as a platform. By doing so, we will leverage widely available low-cost CMOS to build new and economically significant technologies that can be developed and exploited in the UK. There are considerable challenges to be overcome to make such technology possible. We will hybridise two semiconductor systems to integrate efficient photodiode sensors for visible and MIR detection. We will integrate boletric sensing for FIR imaging. We will use design and packaging technologies for thermal isolation and to optimise the performance of each sensor type. We will use hybridised metamaterial and surface plasmon resonance technologies to optimise wavelength discrimination allowing vertical stacking of physically large (i.e. FIR) sensors with visible and MIR sensors.

We ultimate want to demonstrate the world's first ever super-spectral camera.

Thursday, February 11, 2016

Abstract-Multi-spectral materials: hybridisation of optical plasmonic filters, a mid infrared metamaterial absorber and a terahertz metamaterial absorber



James Grant, Iain J. H. McCrindle, and David R. S. Cumming

Multi-spectral imaging systems typically require the cumbersome integration of disparate filtering materials and detectors in order to operate simultaneously in multiple spectral regions. Each distinct waveband must be detected at different spatial locations on a single chip or by separate chips optimised for each band. Here, we report on a single component that optically multiplexes visible, Mid Infrared (4.5 μm) and Terahertz (126 μm) radiation thereby maximising the spectral information density. We hybridise plasmonic and metamaterial structures to form a device capable of simultaneously filtering 15 visible wavelengths and absorbing Mid Infrared and Terahertz. Our synthetic multi-spectral component could be integrated with silicon complementary metal-oxide semiconductor technology where Si photodiodes are available to detect the visible radiation and micro-bolometers available to detect the Infrared/Terahertz and render an inexpensive, mass-producible camera capable of forming coaxial visible, Infrared and Terahertz images.
© 2016 Optical Society of America
Full Article  |  PDF Article

Wednesday, July 29, 2015

Abstract-Metamaterial based terahertz imaging


Escorcia Carranza, Ivonne -  Grant, James -  Gough, John -  Cumming, David R.S. -
http://biblioteca.universia.net/html_bura/ficha/params/title/metamaterial-based-terahertz-imaging/id/61651030.html

This article presents the design of an innovative, low-cost, uncooled, metamaterial based terahertz (THz) focal plane array (FPA). A single pixel is composed of a resonant metamaterial absorber and micro-bolometer sensor integrated in a standard 180 nm CMOS process. The metamaterial is made directly in the metallic and insulating layers available in the six metal layer CMOS foundry process. THz absorption is determined by the geometry of the metamaterial absorber which can be customized for different frequencies. The initial prototype consists of a 5 x 5 pixel array with a pixel size of 30 µm x 30 µm and is readily scalable to more commercially viable array sizes. The FPA imaging capability is demonstrated in a transmission and reflection mode experiment by scanning a metallic object hidden in a manila envelope.

Wednesday, November 27, 2013

Abstract-Multi-Spectral Materials: Hybridisation of Optical Plasmonic Filters and a Terahertz Metamaterial Absorber






Iain J. H. McCrindle, James Grant, Timothy D. Drysdale, David R. S. Cummin
http://onlinelibrary.wiley.com/doi/10.1002/adom.201300408/abstract

Multi-spectral materials, using hybridised plasmonic and metamaterial structures, can simultaneously exhibit unique resonant phenomena over several decades of wavelengths. A multi-spectral material that combines a plasmonic colour filter array and a terahertz metamaterial absorber into a single material is a promising prospect for a coaxial multi-spectral imager operating in the visible, near IR, and terahertz wavebands.