Physics Commons^™

Generation Of Mid-Ir Wavelengths, Deborah Robinson, Robert Hartsock, Kelly Gaffney

STAR Program Research Presentations

Generation of mid-IR wavelengths

Deborah Robinson, Robert Hartsock, and Kelly Gaffney

Abstract

Research to determine basic molecular properties utilizing pump/probe experiments is an on going effort at SLAC. Here we have been given the task to generate mid-IR laser pulses and commission a mid-IR detector for said experiments and research. The mid-IR pulses will be used to probe the changes in molecular properties induced by exciting the electrons in molecules with visible pump pulses. In order to accomplish this, an optical parametric amplifier (OPA) has been set-up and aligned. The pump beam for the OPA is a 40 femtosecond 800nm …

Coupled Photonic Crystal Micro-Cavities With Ultra-Low Threshold Power For Stiumulated Raman Scattering, Qiang Liu, Zhengbiao Ouyang, Sacharia Albin

Electrical & Computer Engineering Faculty Publications

We propose coupled cavities to realize a strong enhancement of the Raman scattering. Five sub cavities are embedded in the photonic crystals. Simulations through finite-difference time-domain (FDTD) method demonstrate that one cavity, which is used to propagate the pump beam at the optical-communication wavelength, has a Q factor as high as 1.254 × 10⁸ and modal volume as small as 0.03μm³ (0.3192(λ/n)³). These parameters result in ultra-small threshold lasing power ~17.7nW and 2.58nW for Stokes and anti-Stokes respectively. The cavities are designed to support the required Stokes and anti-Stokes modal spacing in silicon. The proposed structure …