High-precision grating period measurement.

We introduce a method for measuring a periodic structure, particularly a grating period. The method is based on the high-precision laser Talbot effect. The combination of a rubidium-locked external cavity diode laser and the Talbot interferometer provides an excellent and simple tool for this purpose. Some experimental results are provided to demonstrate the approach.

All-optical wireless wavelength multiplexing and demultiplexing using resonant cavity.

The potential capability of wireless wavelength multiplexing and demultiplexing can enable the next development of smaller photonic counterparts for network architectures. This paper numerically represents a new design of a wireless transmission in C-band infrared wavelengths within two identical resonant cavities between photonic chips. This system consists of an H1 rod-type two-dimensional photonic crystal (PhC) microcavity, which can be operated as both a transmitter and a receiver without interfering with the signal in each PhC waveguide. By using the point-to-point oscillatory light-field exchange between resonant cavities, two independent photonic circuits are linked with each other. The obtained results show that the multi-resonance wavelengths in one chip can be transferred to another chip located far away by ten times the highest resonance wavelength. Such a device can be useful for integrated optical circuit interconnect and small-scale sensors between photonic chips.

High-contrast optical vortex detection using the Talbot effect.

We apply the near-field Talbot effect to distinguish, characterize, and detect optical vortices. We perform experiments with single-, double-, multiple-slit, and grating diffraction. High-contrast image detection is achieved with the Talbot effect of a grating, even for higher than l=±1 orbital angular momentum states. Furthermore, we manipulate the vortex beam with different vortex states and use the Talbot effect for detecting. The experimental results are supported by theoretical simulations and demonstrate that the Talbot effect provides an excellent tool for optical vortex detection.

Analytical and simulation results of a triple micro whispering gallery mode probe system for a 3D blood flow rate sensor.

The whispering gallery mode (WGM) is generated by light propagating within a nonlinear micro-ring resonator, which is modeled and made by an InGaAsP/InP material, and called a Panda ring resonator. An imaging probe can also be formed by the micro-conjugate mirror function for the appropriate Panda ring parameter control. The 3D WGM probe can be generated and used for a 3D sensor head and imaging probe. The analytical details and simulation results are given, in which the simulation results are obtained by using the MATLAB and Optiwave programs. From the obtained results, such a design system can be configured to be a thin-film sensor system that can contact the sample surface for the required measurements The outputs of the system are in the form of a WGM beam, in which the 3D WGM probe is also available with the micro-conjugate mirror function. Such a 3D probe can penetrate into the blood vessel and content, from which the time delay among those probes can be detected and measured, and where finally the blood flow rate can be calculated and the blood content 3D image can also be seen and used for medical diagnosis. The tested results have shown that the blood flow rate of 0.72-1.11 µs-1, with the blood density of 1060 kgm-3, can be obtained.

Realization of the single photon Talbot effect with a spatial light modulator.

We demonstrate the quantum Talbot effect using a beam of single photons produced by parametric down conversion. In contrast to the previous works, we use a programmable spatial light modulator to behave as a diffraction grating. Thus, the investigation of the Talbot diffraction patterns under the variation of grating structure can be easily performed. The influence of spectral bandwidth of the down-converted photons on the diffraction pattern is also investigated. A theoretical model based on the wave nature of photons is presented to explain the Talbot diffraction patterns under varying conditions. The measured diffraction patterns are in good agreement with the theoretical prediction. We are convinced that our study improves the understanding of the quantum Talbot effect.