Moisture-insensitive optical fingerprint scanner based on polarization resolved in-finger scattered light.

A moisture-insensitive optical fingerprint scanner (FPS) that is based on polarization resolved in-finger light is proposed and realized. Incident visible light, which is selectively fed to a fingerprint sample via a polarization beam splitter (PBS), is deemed to be partially scattered backward by tissues associated with the skin of the finger. The backscattered light is mostly index-guided in the ridge comprising the fingerprint, which has a higher refractive index, and is drastically dispersed in the valley, which is typically filled with water or air and so has a lower index.

Birefringent waveguide sensor using a polarizer rotating technique.

A birefringence measurement system is introduced to get high phase resolution for detection of low contents of biochemicals. By using a fixed quarter-wave plate and a rotating polarizer, the phase difference between two orthogonal polarizations is transformed into phase delay of output sinusoidal signal. Analyzing the output phase, birefringence change could be detected with a phase noise of 0.

Refractometric sensor utilizing a vertically coupled polymeric microdisk resonator incorporating a high refractive index overlay.

A refractometric sensor resorting to a vertically coupled polymeric microdisk resonator was demonstrated, estimating the refractive index (RI) of an analyte by monitoring the resonant wavelength shift in its transfer characteristics. The disk resonator was especially overlaid with a high RI TiO2 film, thereby reinforcing the interaction of the evanescent field of its guided mode with the analyte. The sensitivity of the sensor was theoretically and experimentally confirmed to be enhanced by adjusting the overlay thickness.

Integrated optical modulator for signal up-conversion over radio-on-fiber link.

An integrated optical modulator, which consists of a dual-sideband suppressed carrier (DSB-SC) modulator cascaded with a single-sideband (SSB) modulator, is proposed for signal up-conversion over Radio-on-Fiber. Utilizing a single-drive domain inverted structure in both modulators, balanced modulations were obtained without complicated radio frequency (RF) driving circuits and delicate RF phase adjustments. Intermediate frequency (IF) band signal was up-conversed to 60GHz band by using the fabricated device and was transmitted over optical fiber.