arXiv subjects

Mingbin Yu

Publications and source records attributed to Mingbin Yu.

24 records · Page 2Linked to original sources

arXiv2012

Regenerative oscillation and four-wave mixing in graphene optoelectronics

The unique linear and massless band structure of graphene, in a purely two-dimensional Dirac fermionic structure, have led to intense research spanning from condensed matter physics to nanoscale device applications covering the electrical, thermal, mechanical and optical domains. Here we report three consecutive first-observations in graphene-silicon hybrid optoelectronic devices: (1) ultralow power resonant optical bistability; (2) self-induced regenerative oscillations; and (3) coherent four-wave mixing, all at a few femtojoule cavity recirculating energies. These observations, in comparison with control measurements with solely monolithic silicon cavities, are enabled only by the dramatically-large and chi(3) nonlinearities in graphene and the large Q/V ratios in wavelength-localized photonic crystal cavities. These results demonstrate the feasibility and versatility of hybrid two-dimensional graphene-silicon nanophotonic devices for next-generation chip-scale ultrafast optical communications, radio-frequency optoelectronics, and all-optical signal processing.

physics.optics↗

arXiv2011

Selective tuning of high-Q silicon photonic crystal nanocavities via laser-assisted local oxidation

We examine the cavity resonance tuning of high-Q silicon photonic crystal heterostructures by localized laser-assisted thermal oxidation using a 532 nm continuous wave laser focused to a 2.5 mm radius spot-size. The total shift is consistent with the parabolic rate law. A tuning range of up to 8.7 nm is achieved with ~ 30 mW laser powers. Over this tuning range, the cavity Q decreases from 3.2\times10^5 to 1.2\times10^5. Numerical simulations model the temperature distributions in the silicon photonic crystal membrane and the cavity resonance shift from oxidation.

physics.optics↗

arXiv2010

Deterministic integrated tuning of multi-cavity resonances and phase for slow-light in coupled photonic crystal cavities

We present the integrated chip-scale tuning of multiple photonic crystal cavities. The optimized implementation allows effective and precise tuning of multiple cavity resonances (up to ~1.60 nm/mW) and inter-cavity phase (~ 0.038 pi/mW) by direct local temperature tuning on silicon nanomembranes. Through designing the serpentine metal electrodes and careful electron-beam alignment to avoid cavity mode overlap, the coupled photonic crystal L3 cavities preserve their high quality factors. The deterministic resonance and phase control enables switching between the all-optical analogue of electromagnetically-induced-transparency (EIT) to flat-top filter lineshapes, with future applications of trapping photons/photonic transistors and optoelectronic modulators.

physics.optics↗

arXiv2010

Observations of four-wave mixing in slow-light silicon photonic crystal waveguides

Four-wave mixing is observed in a silicon W1 photonic crystal waveguide. The dispersion dependence of the idler conversion efficiency is measured and shown to be enhanced at wavelengths exhibiting slow group velocities. A 12-dB increase in the conversion efficiency is observed. Concurrently, a decrease in the conversion bandwidth is observed due to the increase in group velocity dispersion in the slow-light regime. The experimentally observed conversion efficiencies agree with the numerically modeled results.

physics.optics↗

arXiv2008

Deterministic control of all-optical analogue to electromagnetically induced transparency in coherently-coupled silicon photonic crystal cavities

Quantum coherence in atomic systems has led to fascinating outcomes, such as laser cooling and trapping, Bose-Einstein condensates, and electromagnetically-induced-transparency (EIT). In EIT, the sharp cancellation of medium absorption has led to phenomena such as lasing without inversion, freezing light, and dynamic storage of light in a solid-state system. Similar to atomic systems, EIT-like effects can be observed through classical and optical means. Here we report the first experimental deterministic tuning of all-optical analogue to EIT in coherently-coupled standing-wave photonic crystal cavities. Our observations include transparency-resonance lifetimes more than three times the single loaded cavity, Fano-type lineshapes, and stepwise control of the coherent cavity-cavity interference. Our system, with wavelength-scale localization and coupled to a single waveguide, is analyzed well through the coupled-mode formalism which examines the delay in both transparency- and Fano-like lineshapes. Our observations support applications towards all-optical trapping, stopping and time-reversal of light in a solid-state scalable implementation.

physics.optics↗

arXiv2007

Observation of femto-joule optical bistability involving Fano resonances in high-Q/Vm silicon photonic crystal nanocavities

We observe experimentally optical bistability enhanced through Fano interferences in high-Q localized silicon photonic crystal resonances (Q ~ 30,000 and modal volume ~ 0.98 cubic wavelengths). This phenomenon is analyzed through nonlinear coupled-mode formalism, including the interplay of chi(3) effects such as two-photon absorption and related free-carrier dynamics, and optical Kerr as well as thermal effects and linear losses. Our experimental and theoretical results demonstrate for the first time Fano-resonance based bistable states with switching thresholds of 185 micro-Watt and 4.5 fJ internally stored cavity energy (~ 540 fJ consumed energy) in silicon for scalable optical buffering and logic.

physics.optics↗