A Novel Optical Filter for Removing Bright-Background Using an Enhanced Bacteriorhodopsin Thin Film

In this work, solar-blind UV 4H-SiC avalanche photodetectors were fabricated and tested in linear and Geiger modes. APDs with both PIN and separate absorption and multiplication (SAM) structures were investigated. PIN structures demonstrated higher quantum efficiencies while the SAM structure exhibit lower leakage currents. Deposition of a thin film optical filter on top of the devices was used to provide a high photon rejection ratio of (Stas add value here). However, an external filter showed a better photon rejection ratio compared to the deposited one by about one order of magnitude.

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Optimised Performance of Non-Dispersive Infrared Gas Sensors Using Multilayer Thin Film Bandpass Filters

Coatings ◽

10.3390/coatings8120472 ◽

2018 ◽

Vol 8 (12) ◽

pp. 472 ◽

Cited By ~ 2

Author(s):

Pinggui Wang ◽

Xiuhua Fu ◽

Des Gibson ◽

Lewis Fleming ◽

Sam Ahmadzadeh ◽

...

Keyword(s):

Thin Film ◽

Work Performance ◽

Microwave Plasma ◽

Light Emitting Diode ◽

Spectral Characteristics ◽

Optical Filter ◽

Deposition Process ◽

Bandpass Filters ◽

Temperature Sensitive ◽

Sensor Performance

In this work, performance improvements are described for a low-power consumption non-dispersive infrared (NDIR) methane (CH4) gas sensor using customised optical thin film bandpass filters (BPFs) centered at 3300 nm. BPFs shape the spectral characteristics of the combined mid-infrared III–V based light emitting diode (LED)/photodiode (PD) light source/detector optopair, enhancing the NDIR CH4 sensor performance. The BPFs, deposited using a novel microwave plasma-assisted pulsed DC sputter deposition process, provide room temperature deposition directly onto the temperature-sensitive PD heterostructure. BPFs comprise germanium (Ge) and niobium pentoxide (Nb2O5) alternating high and low refractive index layers, respectively. Two different optical filter designs are progressed with BPF bandwidths (BWs) of 160 and 300 nm. A comparison of the modelled and measured NDIR sensor performance is described, highlighting the maximised signal-to-noise ratio (SNR) and the minimised cross-talk performance benefits. The BPF spectral stability for various environmental temperature and humidity conditions is demonstrated.

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Thermal Fatigue Reliability of Solder Joints in a Thin Film Optical Filter Device

Transactions of the Korean Society of Mechanical Engineers A ◽

10.3795/ksme-a.2004.28.6.677 ◽

2004 ◽

Vol 28 (6) ◽

pp. 677-684

Keyword(s):

Thin Film ◽

Thermal Fatigue ◽

Solder Joints ◽

Optical Filter ◽

Fatigue Reliability ◽

Reliability Of Solder Joints

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The Growth and Properties of Thin-Film Nano-Composites

MRS Proceedings ◽

10.1557/proc-457-387 ◽

1996 ◽

Vol 457 ◽

Author(s):

Keith L Lewis ◽

A M Pitt ◽

A G Culus

Keyword(s):

Thin Film ◽

Optical Filter ◽

Environmental Stability ◽

Nano Composites ◽

Film Properties ◽

Fundamental Study ◽

Cross Sectional ◽

Graded Index ◽

Materials Engineering ◽

Molecular Beam Deposition

ABSTRACTNano-composites allow a materials engineering approach to be exploited to realise specific characteristics in optical thin film ensembles. For example, films can be produced with refractive indices determined by their average composition on the basis of effective medium approximations, so freeing optical designers from the constraints imposed in pure materials. A summary is presented of the progress made in a fundamental study of films based on diverse materials such as fluorides and sulphides, fabricated using molecular beam deposition techniques. The film properties (eg refractive index, surface morphology, environmental stability) are correlated with microstructure (as determined by cross-sectional TEM techniques). The enhanced properties of the films are discussed in relation to the realisation of periodically modulated graded-index structures of the type required for optical filter applications.

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