We demonstrate an integrated polarization beam splitter (PBS) of a simple and compact device geometry with high polarization extinction ratios (PERs). A silicon PBS based on a three-waveguide directional coupler is numerically simulated for optimum device parameters, and fabricated experimentally. The measured PER values of the fabricated PBSs are 40.74 dB and 39.01 dB for transverse electric and transverse magnetic modes, respectively, and their corresponding insertion losses are 0.35 dB on average for a coupler length of about 29.4 μm.

We propose and experimentally demonstrate an ultracompact transverse magnetic (TM) mode pass filter based on a rectangularly-shaped one-dimensional (1-D) photonic crystal silicon waveguide with an extremely high polarization extinction ratio (PER) of >30 dB and a low insertion loss (IL) of ~1 dB. The device structure of the TM mode-pass filter is numerically simulated using a three-dimensional (3-D) finite difference time domain (FDTD) method. The proposed device supports its fundamental TM mode only, whereas the transverse electric (TE) mode is reflected by the 1-D photonic crystals (PhCs). The measured PER of the fabricated TM mode-pass filter is ~34 dB, and the IL is about 1 dB. The entire device length is about 4 μm. Our simulation results predict that the device bandwidth of 30 dB PER is about 200 nm.

We introduce a new method for simultaneously measuring group and phase refractive indices, the dispersion profile, and the physical thickness of transparent plates by using low coherent Fabry-Perot (FP) interferometry without using any mechanical scanning and sample rotation. A broadband infrared light source was used for a fiber-type FP interferometer, and the Fourier transform analysis on the measured interference spectra was performed to determine the refractive indices and thickness of BK7, quartz, and fused silica samples over its wavelength range. The accuracy of the physical thickness of the samples was obtained within an order of 1 μm scale, while that of both the group and the phase refractive indices was within the third decimal point.