DUV coherent light emission from ultracompact microcavity wavelength conversion device
Tomoaki Nambu, Taketo Yano, Soshi Umeda, Naoki Yokoyama, Hiroto Honda, Yasunori Tanaka, Yutaka Maegaki, Yusuke Mori, Masashi Yoshimura, Shuhei Kobayashi, Shuhei Ichikawa, Yasufumi Fujiwara, Ryota Ishii, Yoichi Kawakami, Masahiro Uemukai, Tomoyuki Tanikawa, Ryuji Katayama
Abstract
A unique design of our ultracompact microcavity wavelength conversion device exploits the simple principle that the wavelength conversion efficiency is proportional to the square of the electric field amplitude of enhanced pump light in the microcavity, and expands the range of suitable device materials to include crystals that do not exhibit birefringence or ferroelectricity. Here, as a first step toward practical applications of all-solid-state ultracompact deep-ultraviolet coherent light sources, we adopted a low-birefringence paraelectric SrB 4 O 7 crystal with great potential for wavelength conversion and high transparency down to 130 nm as our device material, and demonstrated 234 nm deep-ultraviolet coherent light generation, whose wavelength band is expected to be used for on-demand disinfection tools that can irradiate the human body.