Papers by Keyword: Integrated Optics

Abstract: An optical 90^o hybrid consisting of a general interference based 4×4 MMI coupler, a phase shifter and a 2×2 MMI coupler was proposed. This device can demodulate optical signal without intersections. The output power formula of this device was derived from theory, and the effect on phase shifter was discussed analytically and numerically. It is not necessary to control phase shifter accurately, a deviation 10^o form perfect phase shift will introduce 2% AC component loss of Q information only.

Abstract: A novel air-hole assisted metaldielectricmetal (MDM) waveguide has been proposed and numerically demonstrated. It has excellent characters including subwavelength mode confinement, chip-scale long propagation length, highly efficient direct bends with compact footprints, and high waveguide isolation with tiny center-to-center separation at the wavelength of 1.55 μm. To prove that the hybrid waveguide could be an ideal candidate for large-scale photonic integration, its characters are all compared with the silicon, photonic crystal, surface plasmon polariton based waveguides.

Abstract: We propose and develop a passive alignment technique of 4 output waveguides of PLC-based 90° OH and a 1×4 PD array. This alignment technique only uses an infrared CCD camera and an infrared light.

Abstract: The paper describes the basic principle and structure of the resonator micro-optic gyro (RMOG), the influence of intensity variation of laser is analyzed for the first time. The relationship between the light intensity input the integrated optical resonator (IOR) and the slope at working range is simulated and analyzed by the optical field overlapping method. The amplitudes of the output square waveforms with different zero biases are simulated and analyzed. The experimental setup is constructed and tested, the test result shows that in order to reach the limited ultimate sensitivity of 15.5 deg/h, it is necessary to restrict the zero bias within 8.1 deg/s under open-loop output scheme.

Abstract: As one of the new optical sensing devices, Resonant Micro-optic Gyro (RMOG) measures the rotation rate due to the resonance frequency difference based on the optical Sagnac effect. In order to reduce the influence of the light path and circuit noise and the output edge pulse signal, the mean filtering algorithm based on Labview is put forward to improve the gyros performance. The mean filtering algorithm is simulated and realized with Labview, which approves that the algorithm is effective in noise restraining. The test of RMOG demonstrates that the zero bias stability is 1.4 °/s during 1 hour with 10-second smoothing.

Abstract: In order to realize the opto-electronic integration of optic gyro, the quasi-planar ridge SOI waveguide resonator is proposed due to its low loss and small bend radius. First, the single mode condition and smallest bend radius were simulated by using the 3-dimension finite difference beam propagation method (3-D BPM). Then the relationship between the sensitivity of gyro and the resonator characteristics, such as radius and coupling coefficient, was analyzed by applying the model of the integrated optical gyro. Based on these simulations, the ridge height and width of the waveguide were 220 nm and 1.2 μm respectively and the smallest bend radius was 600μm. It is shown that the theoretical detection limit of the gyro was 0.031 °/s when the resonator diameter was 5cm and the couplers splitting ratio was 46.7:53.3. This gyro system is suitable for tactical and civil applications.

Abstract: We present a probe of scanning near-field optical microscope (SNOM) with large aperture and high resolution, which is added a metallic dipole nano-antenna onto the tip of the ordinary probe. Based on the FDTD algorithm we investigate numerically the measure results by different aperture probes for the same sample with the incident wavelength of 830nm and the scan height of 10nm. The results show that the resolution of the new probe is 100nm, 75nm, 50 nm, 45 nm, 50 nm, 70nm when the probe aperture is 50nm, 100nm, 130nm, 150nm, 170nm, 200nm respectively, and for the ordinary probe the resolution is 50nm，120 nm,140 nm,180 nm, 200nm, 220nm correspondingly. That is to say the resolution of the ordinary probe decrease rapidly with the increasing of the aperture, however the novel probe can maintain the high resolution.

Abstract: Silicon-On-Insulator (SOI) technology exhibits significant performance advantages over conventional bulk silicon technology in both electronics and optoelectronics. In this chapter we present an overview of recent applications on light emission from SOI materials. Particularly, in our work we used SOI technology to fabricate light emitting diodes (LEDs), which emit around 1130 nm wavelength with an external quantum efficiency of 1.4 × 10−4 at room temperature (corresponding to an internal quantum efficiency close to 1 %). This is almost two orders of magnitude higher than reported earlier for SOI LEDs. This large improvement is due to three carrier confinement mechanisms: geometrical effects, quantum-size effects, and electric field effects. Our lateral p+/p/n+ structure is powered through two very thin silicon slabs adjacent to the p+/p and n+/p junction. Such use of thin silicon films aims to reduce the p+ and n+ contact area and to confine the injected carriers in the central lowly doped p-region. With this approach, we realized an efficient compact infrared light source with high potential switching speed for on-chip integration applications.