Characterization of a wavelength-tunable antenna-coupled infrared microbolometer

Wavelength tuning is demonstrated in an antenna-coupled infrared microbolometer. With a 300-mV control voltage, we observed a tuning range of 0.5 mu m near 10 mu m. A metal-oxide-semiconductor capacitor underneath the antenna arms causes the shift of resonance wavelength with applied voltage. We develop a device model that agrees well with measured results

Wavelength tuning of an antenna-coupled infrared microbolometer

Wavelength tuning is demonstrated in an antenna-coupled infrared microbolometer. With a 300-mV control voltage, we observed a tuning range of 0.15 mum near 10 mum. A metal-oxide-semiconductor capacitor underneath the antenna arms causes the shift of resonance wavelength with applied voltage. We develop a device model that agrees with measured results

EEG Biofeedback as a Treatment for Substance Use Disorders: Review, Rating of Efficacy, and Recommendations for Further Research

Electroencephalographic (EEG) biofeedback has been employed in substance use disorder (SUD) over the last three decades. The SUD is a complex series of disorders with frequent comorbidities and EEG abnormalities of several types. EEG biofeedback has been employed in conjunction with other therapies and may be useful in enhancing certain outcomes of therapy. Based on published clinical studies and employing efficacy criteria adapted by the Association for Applied Psychophysiology and Biofeedback and the International Society for Neurofeedback and Research, alpha theta training—either alone for alcoholism or in combination with beta training for stimulant and mixed substance abuse and combined with residential treatment programs, is probably efficacious. Considerations of further research design taking these factors into account are discussed and descriptions of contemporary research are given

Measurement Of The Resonant Lengths Of Infrared Dipole Antennas

The resonant lengths of infrared dipole antennas at 10.6 and 3.39 μm are experimentally investigated. For this purpose, submicron-sized microbolometers coupled to dipole antennas with lengths between 0.7 and 20 μm were fabricated on a SiO2-on-Si substrate. The response of the detector to 10.6 μm radiation shows a first resonance for an antenna length between 1.0 and 2.5 μm. A subsequent zero and a second attenuated resonance are observed as the antenna length increases. Similar behavior is observed for illumination at 3.39 μm, with a first resonance occurring at a length shorter than 1 μm. The results permit evaluation of an effective dielectric permittivity and shows the effect of the surface impedance of the metal on the propagation of current-wave on the antenna. The resonance behavior is further studied by changing the irradiation conditions of the detectors. Air-side and substrate-side illumination exhibit identical resonant antenna lengths, but different efficiencies of power collection. The antenna patterns as a function of incident angle have also been measured at 10.6 μm, showing a transition from a primary broadside lobe to the development of side lobes for longer antennas. Finally, an antenna response is measured at visible frequencies. Our measurements point out similarities, as well as differences, between infrared antennas and their counterparts at microwave frequencies, and provide insights useful for the design optimization of planar infrared antennas

Responsivity Of Infrared Antenna-Coupled Microbolometers For Air-Side And Substrate-Side Illumination

The response of an antenna-coupled microbolometer fabricated on a Si wafer coated on both sides with thin films of SiO2 was measured for two types of illumination: through the substrate and from the air side. The measurement was performed in the spectral range from 9.22 to 10.84 μm. Both cases are modeled by using the transmission, reflection, and absorption properties of the three-layer wafer. The spectral characteristics of the SiO2 thin film play a major role in the response of the detector. The responses of the sensor to the parallel and perpendicular polarizations are modeled by using two main contributions: the heating by absorption in the SiO2 layer and the coupling of incident flux on the bolometer. Fitting this model to the experimental data allows us to conclude that the antenna response is the result of the incident flux coming from the substrate side. When the device is illuminated from the air side, the antenna signal results from the flux reflected at the film/substrate interface. The efficiencies of the contributions to the antenna signal coming from the substrate or from the air side have been obtained from the data fitted with the model. The substrate-side contribution is 50 times larger than the air-side contribution, confirming the theory of lithographic antenna on a dielectric substrate