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Spectroscopic analysis has been widely used in medical research and healthcare testing including trace chemical, biochemical and immunoassay. We have developed a chip based spectrometer - SpectroChip based on novel MEMS technology. It has a spectral resolution of 5 nm with a spectral range of 350 1100 nm and a signal to noise ratio of 300:1. We have built a rapid test reader for COVID-19 antibody and antigen detection using our SpectroChip. Our SpectroChip technology will play a key role not only in disease control for COVID-19 pandemic but also in telemedicine and homecare health monitoring.

2D analytical model (Ko et al. (2016)) based on the geometry of the commercial coater system can calculate more effectively the profiles of LVFs. The model and experimental results (within 25%–75% thickness range) for LVF zone width, transmission spectrum and a thin film profile measurement of LVF shows good agreement with high degree of accuracy and the profile distribution exhibits a high degree of linearity.

A generalized optimization process to reduce the aberration of a concave grating is developed. The approach has a dramatic improvement in aberration reduction and spectral resolution. Calculated result is in good agreement with measurement.

The blazed grating with the Rowland structure has the advantage of self-focusing and is chosen as the major component in the spectrometer chip. In simulations for the blaze angle design in visible spectrum, we discover the phenomenon of the double reflection diffraction. Its cause and parameter space are discussed. The spectrometer utilizing the phenomenon has similar performance to the grating with the ordinary diffraction and is easier to manufacture in microelectromechanical systems (MEMS) technology. The discovery will greatly ease the design of the spectrometer chip.

The aim of the paper is to propose an idea of photonic switch using 2D magnetic photonic crystal (Magneto-PC) structures, which is made of ferromagnetic material. The photonic switch is controlled by an external magnetic field under two magnetization conditions in the hysteresis curve: (1) the saturation magnetization (labeled as the Bs point in the hysteresis curve); and (2) non-magnetization state (labeled as the Hc point in the hysteresis curve). The design of the 2D Magneto-PC consists of three rows of one dimensional array of ferromagnetic rods, called the "3-by-N structure". The variations in the transmission rate and the reflection rate at wavelength 650 nm for the TE and the TM waves, respectively, under these two magnetization conditions in the ferromagnetic hysteresis curve were observed. The simulation is carried out by the finite-difference time-domain (FDTD) method.