Optical modulator on silicon employing germanium quantum wells

Jonathan Roth — 2008-02-26T00:46:37-00:00

Opt. Express, Vol. 15, No. 9. (30 April 2007), pp. 5851-5859.

We demonstrate an electroabsorption modulator on a silicon substrate based on the quantum confined Stark effect in strained germanium quantum wells with silicon-germanium barriers. The peak contrast ratio is 7.3 dB at 1457 nm for a 10 V swing, and exceeds 3 dB from 1441 nm to 1461 nm. The novel side-entry structure employs an asymmetric Fabry-Perot resonator at oblique incidence. Unlike waveguide modulators, the design is insensitive to positional misalignment, maintaining > 3 dB contrast while translating the incident beam 87 μm and 460 μm in orthogonal directions. Since the optical ports are on the substrate edges, the wafer top and bottom are left free for electrical interconnections and thermal management.

Photonic logic NORgate based on two symmetric microring resonators

TA Ibrahim — 2008-02-22T02:53:54-00:00

Opt. Lett., Vol. 29, No. 23. (1 December 2004), pp. 2779-2781.

We demonstrate an all-optical NOR logic gate based on symmetric GaAs–AlGaAs microring resonators whose resonances are closely matched. Two input pump data streams are tuned close to one resonance of the symmetric microrings to switch a probe beam tuned to another resonance by two-photon absorption. The switching energy of the gate is 20 pJ/pulse, and the switching window is 40 ps, limited by the carrier lifetime. The use of two rings provides for better cascading in photonic logic circuits because of the higher number of available ports.

CiteULike: marcoescobar's Kuo

Optical modulator on silicon employing germanium quantum wells

Photonic logic NORgate based on two symmetric microring resonators