Broadband Polarization Splitter-Rotator and the Application in WDM Receiver

Abstract

Polarization sensitivity is a severe problem in photonic integration devices and chips based on the high-index contrast Si/SiO 2 system. In this paper, a broadband silicon polarization splitter-rotator (PSR) comprised of a bi-level taper and a counter-tapered coupler is proposed with a large fabrication tolerance. The measured insertion loss is lower than 0.7 dB/0.73 dB for the wavelength range from 1470 to 1580 nm with a crosstalk lower than −12.1 dB/−14.7 dB for TE and TM polarization input, respectively. By integrating the PSR with silicon arrayed waveguide gratings and germanium photodetectors (PDs) on a single chip, a polarization-insensitive wavelength-division-multiplexing (WDM) receiver is demonstrated with a polarization-dependent loss as low as 1.21 dB. High-speed operations are also achieved with clear eyes at 10 Gb/s.

On‐Chip Light Polarization Management by Mapping the Polarization Information to Phase Shift

“…As a benchmark, a PRS is constructed with the PPM. The comparison of the PPM-based PRS with the PRS experimentally demonstrated in literature [17,19,[21][22][23][24][25][27][28][29][30]32,33,38,41,45,[47][48][49]51,52,54] is listed in Note S12, Supporting Information. The PPM-based PRS shows good overall performance.…”

“…The essence of the rotation in a waveguide is symmetry breaking. Conventionally, the asymmetric directional coupling [ 17–28 ] and TM 0 − TE 1 mode evolution [ 29–54 ] concepts are widely employed for symmetry breaking owing to their fabrication‐friendly nature. However, they are not extensively accepted as the ideal choices in dense integration due to their hundreds‐of‐micrometer level size.…”

Metamaterial‐enabled Fully On‐Chip Polarization‐Handling Devices

“…For example, asymmetric directional couplers (ADCs) are commonly used for polarization manipulation by matching the effective indices of TM and TE modes in adjacent waveguides. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] It provides the best overall performance, while high fabrication accuracy is usually required. Adiabatic coupling is another widely studied method for polarization conversion, achieved by polarization hybridization processes with asymmetric structure along the vertical direction.…”

T-shaped reflective polarizer under second Bragg incidence

“…The polarizer [1][2][3][4][5] can split the incident light into two mutually orthogonal polarized lights, which plays an important role in the field of terahertz devices [6], infrared telecom [7], information technology [8], information processing [9][10][11], imaging [12][13][14][15], optical storage [16][17][18][19], and polarization detection of light [20][21][22][23]. The conventional polarization separators are usually based on the birefringence of crystal, and the size is generally in the order of millimeter.…”