Currently available semiconductor lasers for spectroscopy in the near- and mid-infrared region based on direct band-to-band transitions as gallium-arsenide, indium-phosphide, antimonides and lead-salt containing compounds will be discussed together with the main features of different tunable diode-laser absorption spectrometers for trace gas analysis. Measurements of atmospheric carbon dioxide ...

In this paper, we present an approach to develop an optical gas leak sensor that can be used to measure ethylene, dimethyl ether, and methane. The sensor is designed based on the principles of IR absorption spectrum detection, and comprises two crossed elliptical surfaces with a folded reflection-type optical path. We first analyze the optical path and the use of this structure to design a mini...

Whispering-gallery mode temperature microsensors have been demonstrated to have extremely high accuracy. Previous experiments have been limited to indirect sensor heating by externally heating the local environment. In this paper, we coated PDMS films directly onto an electrical resistive wire as sensors, allowing on-chip dynamic temperature measurement. The effects of sensor size are discussed...

This paper presents a complete low-voltage 3V single supply analog lock-in amplifier (LIA) based on phase sensitive detection technique (PSD) for processing AC sensor signals buried in noise in embedded wireless applications. Reference and bias sensor signals are provided by a quadrature oscillator. Experimental results confirm the capability of the proposed lock-in amplifier to effectively rec...

A graphene-based long-period fiber grating (LPFG) surface plasmon resonance (SPR) sensor is proposed. A monolayer of graphene is coated onto the Ag film surface of the LPFG SPR sensor, which increases the intensity of the evanescent field on the surface of the fiber and thereby enhances the interaction between the SPR wave and molecules. Such features significantly improve the sensitivity of th...

Time-of-Flight Sensing In article number 2100159, Kyusang Lee and co-workers demonstrate a neuron-like resistive timeof-flight sensor method for 3D sensing, with implications in light-detection ranging (LiDAR),automotive vehicles, biomedical vivo imaging, augmented/virtual reality.

We present a viscometric affinity biosensor for continuous monitoring of glucose in biological fluids such as blood and plasma. The sensing principle of this chemico-mechanical sensor is based upon the viscosity variation of a sensitive fluid with glucose concentration. Basically, this device includes both an actuating and a sensing piezoelectric diaphragms as well as a flow-resistive microchan...