ph500084b_si_002.mov (81.47 kB)
Resolving Light Handedness with an on-Chip Silicon Microdisk
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posted on 2014-09-17, 00:00 authored by Francisco J. Rodríguez-Fortuño, Isaac Barber-Sanz, Daniel Puerto, Amadeu Griol, Alejandro MartínezThe efficient manipulation of circularly
polarized light with the
proper handedness is key in many photonic applications. Chiral structures
are capable of distinguishing photon handedness, but while photons
with the right polarization are captured, those of opposite handedness
are rejected. In this work, we demonstrate a planar photonic nanostructure
with no chirality consisting of a silicon microdisk coupled to two
waveguides. The device distinguishes the handedness of an incoming
circularly polarized light beam by driving photons with opposite spins
toward different waveguides. Experimental results are in close agreement
with numerical results, which predict extinction ratios over 18 dB
in a 20 nm bandwidth. Owing to reciprocity, the device can also emit
right or left circular polarization depending on the chosen feeding
waveguide. Although implemented here on a CMOS-compatible platform
working at telecom wavelengths, the fundamental approach is general
and can be extended to any frequency regime and technological platform.