Research projects

When utilizing ultrafast nonlinear optics such as four-wave mixing in a fiber, we can generate quantum correlation among frequency modes of a laser pulse propagating through the fiber. First, we constructed a multimode quantum theory of nonlinear propagation in optical fibers, where we can extract orthogonal eigenfunctions from a broad spectrum. Using this theory, we proved that higher photon-number density squeezing can be obtained up to much higher eigenmodes via nonlinear pulse propagation. Furthermore, we demonstrated that four-mode cluster states in any combinations can be generated among the frequency modes in a laser pulse propagating through a fiber when the initial spectral phase are adaptively shaped.

Development of component technologies and demonstration of laser power scaling were performed for trivalent Praseodymium doped fluoride lasers pumped by blue InGaN diode-lasers (LD) to renovate visible and deep ultraviolet coherent light sources that have been provided by 2nd-4th harmonics of near-infrared lasers.By employing four 3.5-W InGaN LDs, CW lasers at red(4.8W) and green (1.8W), active Q-switching(1W, 5kHz) and its intracavity-SHG(60mW, 7,7kHz), passive Q-switching(1.2W, 105kHz) and its SHG(76mW, 50kHz), and CW mode-locking were achieved.