Xionggui Tang

A novel scheme for 1×N optical power splitter

A novel 1 × N optical power splitter has been proposed, to realize the desired specific optical power splitting, in which the asymmetric Y-branch waveguides based on total internal reflection have been introduced. The simulated results show that the arbitrary expected splitting can be achieved in the device. The device has been fabricated by using polymer materials, and it experimentally exhibits good uniformity at optical power output ports, which is consistent with the simulation prediction. The novel 1 × N optical power splitter has wide potential application in the integrated optical system.

Design and analysis of a novel tunable optical power splitter

A novel tunable optical power splitter, with a Y-branch waveguide based on the total internal reflection and a microprism with tunable index refraction, is presented. Numerical simulation of its optical performance shows that a high dynamic range, low optical loss, and relatively low wavelength-dependence can be achieved. This component offers numerous advantages such as ease for fabrication, low cost, and compact size, which are very useful for potential application in integrated optical devices.

Characteristics of dissipative solitons in an all-fiber thulium-doped fiber ring laser

Abstract. We numerically investigate the output characteristics of dissipative solitons (DSs) in a thulium-doped fiber ring laser mode-locked by a semiconductor saturable absorber mirror (SESAM). It is shown that DSs could be formed with the SESAM acting as a mode-locker and a filtering-equivalent component. The pump power, together with the net-cavity dispersion, determines the properties of the generated DSs. The numerical results qualitatively match with previously reported experimental observations. The pulse compression of the generated DSs is numerically demonstrated by using a segment of single-mode fiber with anomalous dispersion as an external pulse compressor. The corresponding compressed pulses have a minimum duration of 450 fs.

Novel Approach for Controllable Polarization Beam Splitter: Design and Simulation

A novel controllable polarization beam splitter is designed by using the modified Y-branch waveguide structure, in which the nematic liquid crystal is introduced. The optical performance of the polarization beam splitter is numerically investigated by the beam propagation method. The results show that not only can high extinction ratio and low optical loss be easily achieved, but also the output ports for TE and TM modes can be dynamically interchangeable in our configuration. Moreover, the proposed polarization beam splitter has little wavelength dependence and large fabrication tolerance. This firstly proposed device provides a unique approach for the manipulation of polarization splitting, which has wide potential application in the photonic integrated circuits.

Simulation for effect of process parameters on surface profile in thick film photolithography

The microstructure with high fidelity is very important while being used as micro-optical component, because the performance tightly depends on the profile quality of microstructure. Optical lithography method based on thick film resist plays an increasing important role in fabrication for microstructure. However, the profile quality of the microstructure is greatly affected by process parameters adopted in the experiment. In this paper, the effect of illumination wavelength, gap distance and absorption coefficient on the profile quality after development has been simulated, analyzed and discussed in detail, by using the model for thick film lithography. The simulated results show that these process parameters have a great impact on the profile quality of microstructures, which it is helpful for process optimization and profile control of thick film photolithography.

Poling and characterization of a novel organic/polymer electro-optic material

Electro-optic organic/polymer material is important for the fabrication of polymer integrated optic-electronic devices and organic sensors. Recently, a novel organic high μβ value chromophore FFC have been synthesized by molecular design. The absorption spectrum in 400-4000 cm-1 is measured for the material, and the measurement result shows that the absorption loss is negligibly small. An organic/polymer high electro-optic activity material FFC/PSU is obtained by dissolving guest FFC (wt. 20%) and a host polysulfone (PSU) in a solvent. The resolvability of cyclohexanone for the material is satisfactory by comparison with other solvents experimentally, and the preparation of FFC/PSU thin film is ease relatively. The materiel is poled by electric field-assisted contact poling, and the near optimum poling condition is determined by adjusting poling parameters as pre-curing duration, poling temperature and poling voltage etc. The electro-optic coefficient of the material is measured as high as 130pm/V by using the widely accepted simple reflection technique. The investigation indicates that the FFC/PSU has excellent characteristics, such as high electro-optic coefficient, low absorption loss, good thermal stability and capability for withstanding the subsequent process techniques, suitable for the fabrication of high-performance integrated optic-electronic devices and sensors.

A W-Band Frequency Tracing Transceiver System

In millimeter-wave, phase-locked oscillators are often used because the frequency drift of oscillators is very large. However, they are very complex. In this paper, a W-band frequency tracing transceiver system is presented and tested, which is used for digital communication. Although the communication distance is less than that of phase-locked systems, the scheme is simple and the cost is low.

Numerical investigation of dissipative soliton generation in an all-fiber thulium-doped fiber ring laser

We numerically demonstrate the dissipative soliton generation in an all-fiber mode-locked thulium-doped fiber ring laser. It is shown that dissipative solitons could be formed with a SESAM acting as a mode-locker and a filtering-equivalent component.

Numerical investigation of polarization rotation locking of vector solitons in a fiber ring laser

Polarization rotation of vector solitons are numerically investigated in a fiber ring laser mode-locked with SESAM. The results show that the polarization rotation locked vector solitons can be formed in the fiber laser.

Variational Effective Index Analysis of Organic/Polymer Rib Optical Waveguide

Organic/Polymer rib optical waveguide is an important component in polymeric integrated optoelectronic devices as electro-optic modulators. By employing effective index method to calculate the transverse refractive index distribution and effective index of polymer rib waveguide, the optical field distribution in each region is expressed as piecewise functions approximately. Based on the scalar wave equation that governs the guided modes, the variational parameter is determined by variational method for obtaining accuracy transverse optical field distribution. The dispersion characteristics and transverse field distributions of the fundamental and higher order modes are analyzed for polymer rib multimode waveguide. An algorithm is implemented to investigate the effect of the structure parameters and dimensions on the dispersion characteristics, and the transverse optical intensity distributions of the fundamental and higher order modes for TM,TE modes are calculated. The approach has advantages such as high precision, small calculation complexity and high efficiency, which will provide theoretical reference and optimization method for the fabrication of polymeric electro-optic devices.