Monolithically integrated compact 281 µm long arbitrary polarization to TE transformer

This paper introduces a compact building block for an integrated polarization transformer that converts any arbitrary polarization state of input light into a pure transverse electric (TE) polarization. The proposed design combines partial polarization converters with a bimodal phase-shifting section to achieve efficient conversion of arbitrary input polarizations to TE polarization on the chip. The performance of the proposed building block is validated through theoretical analysis, simulations, and experimental measurements of a fabricated device, demonstrating a mode loss of only 0.75 dB at the wavelength of 1.526 µm. Simulations indicate that the design can achieve a mode loss of less than 0.25 dB with a broad operational bandwidth exceeding 40 nm, providing improved phase control.