Toward calibration-free Mach–Zehnder switches for next-generation silicon photonics

• DOI: 10.1364/prj.447478
• Publication Date: 2022-01-25T20:00:08Z
• Authors: Lijia Song; Tangnan Chen; Weixi Liu; Hongxuan Liu; Yingying Peng; Zejie Yu; Huan Li; Yaocheng Shi; Daoxin Dai
• Keywords: 0103 physical sciences; 01 natural sciences

Silicon photonic Mach–Zehnder switches (MZSs) have been extensively investigated as a promising candidate for optical systems. However, conventional <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:mn>2</mml:mn> <mml:mo>×</mml:mo> </mml:mrow> </mml:math> MZSs are usually prone to the size variations of arm waveguides due imperfect fabrication, resulting in considerable random phase imbalance between two arms, thereby imposing significant challenges further developing next-generation id="m2"> <mml:mi mathvariant="italic">N</mml:mi> MZSs. Here we propose novel design toward calibration-free id="m3"> and id="m4"> MZSs, employing optimally widened waveguides, enabled by compact tapered Euler S-bends with incorporated mode filters. With standard 180 nm CMOS foundry processes, more than thirty id="m5"> one id="m6"> <mml:mn>4</mml:mn> Benes MZS new fabricated characterized. Compared their counterparts 0.45-μm-wide present id="m7"> exhibit reduction imbalance. The measured extinction ratios id="m8"> id="m9"> operating all-cross state 27-49 dB id="m10"> <mml:mo form="prefix">∼</mml:mo> <mml:mn>20</mml:mn> <mml:mtext> </mml:mtext> <mml:mi>dB</mml:mi> across wavelength range id="m11"> <mml:mn>60</mml:mn> <mml:mi>nm</mml:mi> , respectively, even without any calibrations. This work paves way large-scale id="m12"> silicon photonics.