Schottky MSM junctions for carrier depletion in silicon photonic crystal microcavities

Abstract

Collection of free carriers is a key issue in silicon photonics devices. We show that a lateral metal-semiconductor-metal Schottky junction is an efficient and simple way of dealing with that issue in a photonic crystal microcavity. Using a simple electrode design, and taking into account the optical mode profile, the resulting carrier distribution in the structure is calculated. We show that the corresponding effective free carrier lifetime can be reduced by 50 times when the bias is tuned. This allows one to maintain a high cavity quality factor under strong optical injection. In the fabricated structures, carrier depletion is correlated with transmission spectra and directly visualized by Electron Beam Induced Current pictures. These measurements demonstrate the validity of this carrier extraction principle. The design can still be optimized in order to obtain full carrier depletion at a smaller energy cost.

Effective thermal resistance of a photonic crystal microcavity

“…The applied bias is 10 V corresponding to a partial depletion of the photonic crystal structure. The lateral width of the depletion region is around 1.5 μm as confirmed by electron beam induced current measurements [14]. The photocurrent I increases regularly as the input power is increased and saturates above 800 μW.…”

“…The resonance wavelength of the cavity is 1538 nm with a quality factor around 40,000. The electrical characteristics of the metal-semiconductor-metal device and its photoresponse are described in detail in [13,14]. Carrier depletion is controlled by the applied bias.…”

In‐Plane Photonic Crystal Devices using Fano Resonances

“…This can be implemented using either a p–i–n junction or a metal–semiconductor–metal (MSM) structure. In fact, such implementations are very well known for carrier extraction across standard strip waveguides and photonic crystal cavities . A combination of these technologies with Fano switches could potentially help in achieving faster all‐optical switches.…”

Small and Large Signal Analysis of Photonic Crystal Fano Laser

“…In the second case, we investigate the response of the FL to modulation of the nanocavity frequency. This may be implemented by various approaches: (i) Dynamic modulation of nanocavity resonance frequency by applying voltage to the electrodes placed near it [19]; (ii) Modifying the nanocavity resonance frequency, without changing its quality factor, by moving a near-field probe vertically and laterally in the nanocavity [20]; (iii) Modulation of the nanocavity resonance frequency, by means of optical nonlinearities -i.e., via dispersion of the optically excited free carriers [21,22]. Varying the modulation frequency in the range of 1GHz ≤ f ≤ 30 THz, we calculate the FM amplitude.…”