My research basically contributes on instrumentations to the cosmology, in particular the polarization of the cosmic microwave background (CMB). This can be the probe to understand the early universe, called as the inflation theory. I have contributed on the development of the new technology of broadband anti-reflection coating using ultra-short pulsed laser ablation, and its application for optical elements of telescopes, such as a half-wave plate, an infrared cut filter, and an optical window. I also work on the simulation of cosmological output from our instrumental input.