Lifetime of photogenerated carriers in silicon-on-insulator rib waveguides

Abstract

The lifetime of photogenerated carriers in silicon-on-insulator rib waveguides is studied in connection with the optical loss they produce via nonlinear absorption. We present an analytical model as well as two-dimensional numerical simulation of carrier transport to elucidate the dependence of the carrier density on the geometrical features of the waveguide. The results suggest that effective carrier lifetimes of ⩽1ns can be obtained in submicron waveguides resulting in negligible nonlinear absorption. It is also shown that the lifetime and, hence, carrier density can be further reduced by application of a reverse bias pn junction.

Optical bistability and pulsating behaviour in Silicon-On-Insulator ring resonator structures

“…From this, a carrier relaxation constant of τ carr ≈ 5.3×10 7 N s with N[cm −3 ] the carrier density and a thermal relaxation constant of τ th ≈ 65ns were derived. These relaxation times are in close agreement with the results obtained in [8,9,10,4,5]. The different nonlinear contributions to the refractive index change inside the cavity, which are responsible for the shift of the resonance wavelength are plotted in Fig.…”

Raman Amplification and Superluminal Propagation of Ultrafast Pulses Based on Loop Silicon Waveguides: Theoretical Modeling and Performance

“…According to literatures [22,[27][28][29], the system parameters may be determined Figure 2 shows the normalized shapes of output signal and reference pulses at port B after transmitting a loop distance. The peak powers of input signal and pump pulses corresponds to −10 dβm, and 34.77 dβm, respectively.…”

“…where n is the carriers density, is the reduced Planck constant, and τ eff is the relevant effective recombination lifetime for free carrier, denoted by [22] …”

Free carrier lifetime modification for silicon waveguide based devices

“…However they appear less effective at high powers due to carrier screening of the reverse bias voltage [3,4]. Scaling the waveguide to sub-micrometer sized dimensions can reduce the effective lifetime of carriers due to enhanced surface recombination [5,6], however in that case the problem of high coupling losses has to be addressed.…”