A novel method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dualwavelength metrology which employs heterodyne detection, the method developed in this work utilizes direct detection of interference fringes of two He-Ne lasers as well as a less precise stepper motor open-loop position control system to perform its measu...

We observed the effect of radiation pressure on the angular sensing and control system of the Laser Interferometer Gravitational-Wave Observatory (LIGO) interferometer's core optics at LIGO Hanford Observatory. This is the first measurement of this effect in a complete gravitational-wave interferometer. Only one of the two angular modes survives with feedback control, because the other mode is ...

We propose and demonstrate a pressure sensor based on a micro air bubble at the end facet of a single mode fiber fusion spliced with a silica tube. When immersed into the liquid such as water, the air bubble essentially acts as a Fabry-Pérot interferometer cavity. Such a cavity can be compressed by the environmental pressure and the sensitivity obtained is >1000 nm/kPa, at least one order of ma...

A method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dual-wavelength metrology, which employs heterodyne detection, the method developed in this work utilizes direct detection of interference fringes of two He-Ne lasers as well as a less precise stepper motor open-loop position control system to perform its measureme...

The sensitivity of interferometers with linear polarizers to the CMB E and B mode are variant under the rotation of the polarizer frame, while interferometer with circular polarizers are equally sensitive to E and B mode. We present analytically and numerically that the diagonal elements of window functions for CMB E/B power spectra are maximized in interferometric measurement of linear polariz...

We present an instructional undergraduate laboratory that introduces the student to an acousto-optic modulator (AOM) in the context of an optical heterodyning experiment. A moving diffraction grating is used to illustrate the internal functioning of an acousto-optic modulator and to make optical heterodyning experiments accessible to any undergraduate laboratory. The concepts and techniques pre...