Passive, broadband and low-frequency suppression of laser amplitude noise to the shot-noise limit using hollow-core fibre

We use hollow-core fibre to preserve the spectrum and temporal profile of picosecond laser pulses in CBD to suppress 2.6 dB of amplitude noise at MHz noise frequencies, to within 0.01 dB of the shot-noise limit. We provide an enhanced version of the CBD scheme that concatenates circuits to suppress over multiple frequencies and over broad frequency ranges --- we perform a first demonstration that reduces total excess amplitude noise, between 2 - 6 MHz, by 85%. These demonstrations enable passive, broad-band, all-guided fibre laser technology operating at the shot-noise limit.Comment: 8 pages, 8 figure

Passive, Broadband, and Low-Frequency Suppression of Laser Amplitude Noise to the Shot-Noise Limit Using a Hollow-Core Fiber

Reducing noise to the shot-noise limit is a challenge for laser development for ultrasensitive applications in precision sensing and fundamental science. We use hollow-core fiber in a collinear-balanced-detection scheme to suppress 2.6 dB of amplitude noise to within 0.01 dB of the shot-noise limit, while simultaneously preserving the spectrum and temporal profile of picosecond laser pulses. We also provide an enhanced version of the scheme that concatenates multiple circuits for suppression over many frequencies and broad frequency ranges. We perform a first demonstration of this method and reduce total excess amplitude noise, between 2 and 6 MHz, by 85%. These demonstrations enable passive, broadband, all-guided fiber-laser technology operating at the shot-noise limit.</p

Passive, Broadband, and Low-Frequency Suppression of Laser Amplitude Noise to the Shot-Noise Limit Using a Hollow-Core Fiber

Reducing noise to the shot-noise limit is a challenge for laser development for ultrasensitive applications in precision sensing and fundamental science. We use hollow-core fiber in a collinear-balanced-detection scheme to suppress 2.6 dB of amplitude noise to within 0.01 dB of the shot-noise limit, while simultaneously preserving the spectrum and temporal profile of picosecond laser pulses. We also provide an enhanced version of the scheme that concatenates multiple circuits for suppression over many frequencies and broad frequency ranges. We perform a first demonstration of this method and reduce total excess amplitude noise, between 2 and 6 MHz, by 85%. These demonstrations enable passive, broadband, all-guided fiber-laser technology operating at the shot-noise limit.</p

Absolute multilateration between spheres

Environmental effects typically limit the accuracy of large scale coordinate measurements in applications such as aircraft production and particle accelerator alignment. This paper presents an initial design for a novel measurement technique with analysis and simulation showing that that it could overcome the environmental limitations to provide a step change in large scale coordinate measurement accuracy. Referred to as absolute multilateration between spheres (AMS), it involves using absolute distance interferometry to directly measure the distances between pairs of plain steel spheres. A large portion of each sphere remains accessible as a reference datum, while the laser path can be shielded from environmental disturbances. As a single scale bar this can provide accurate scale information to be used for instrument verification or network measurement scaling. Since spheres can be simultaneously measured from multiple directions, it also allows highly accurate multilateration-based coordinate measurements to act as a large scale datum structure for localized measurements, or to be integrated within assembly tooling, coordinate measurement machines or robotic machinery. Analysis and simulation show that AMS can be self-aligned to achieve a theoretical combined standard uncertainty for the independent uncertainties of an individual 1 m scale bar of approximately 0.49 µm. It is also shown that combined with a 1 µm m−1 standard uncertainty in the central reference system this could result in coordinate standard uncertainty magnitudes of 42 µm over a slender 1 m by 20 m network. This would be a sufficient step change in accuracy to enable next generation aerospace structures with natural laminar flow and part-topart interchangeability