Demonstration of frequency dependent squeezing for next generation GW detectors

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H02095
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: National Astronomical Observatory of Japan
• Principal Investigator: Flaminio Raffaele 国立天文台, 重力波プロジェクト推進室, 特任教授 (10723108)
• Co-Investigator(Kenkyū-buntansha): 宗宮 健太郎 東京工業大学, 理学院, 准教授 (10582603) ; 辰巳 大輔 国立天文台, 光赤外研究部, 助教 (70333276)
• Co-Investigator(Renkei-kenkyūsha): Aso Yoichi 国立天文台, 重力波プロジェクト推進室, 准教授 (10568174) ; Leonardi Matteo 国立天文台, 重力波プロジェクト推進室, 助教 (90816448)
• Research Collaborator: Takahashi Ryutaro ; Barsuglia Matteo ; Capocasa Eleonora ; Guo Yuefan
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: gravitational wave / quantum noise / squeezed vacuum / filter cavity

Outline of Final Research Achievements

The final goal of this research is to demonstrate the realization of a frequency dependent squeezed vacuum source to improve the sensitivity of gravitational wave detectors. To this purpose a squeezed vacuum source should be coupled with a long optical cavity with high finesse and low losses, called filter cavity.
The first step of this research was to study the specifications of the filter cavity. The result of this study were published on Physical Review D. Based on this study a 300 m long filter cavity was built and installed. In parallel the components for the squeezed vacuum source were installed on an optical bench close to the cavity. Two laser beams, one green and one infrared were then injected into the filter cavity and the cavity was locked at the resonance using the green beam. Using this setup it was possible to measure the optical losses of the cavity. These were found to be in agreement with the requirements. The result of this test has been submitted for publication.

Free Research Field

Gravitational Wave Astronomy