اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدSupport-Area Dependence of Vibration-Insensitive Optical Cavities
149
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
The vibration sensitivities of optical cavities depending on the support-area were investigated both numerically and experimentally. We performed the numerical simulation with two models; one with total constraint over the support area, and the other with only vertical constraint. A support-area-size insensitive optimal support condition could be found by the numerical simulation. The support-area was determined in the experiment by a Viton rubber pad. The vertical, transverse, and longitudinal vibration sensitivities were measured experimentally. The experimental result agreed with the numerical simulation with a sliding model (only vertical constraint).
قيم البحث
اقرأ أيضاً
We present two ultra-stable lasers based on two vibration insensitive cavity designs, one with vertical optical axis geometry, the other horizontal. Ultra-stable cavities are constructed with fused silica mirror substrates, shown to decrease the ther
mal noise limit, in order to improve the frequency stability over previous designs. Vibration sensitivity components measured are equal to or better than 1.5e-11 per m.s^-2 for each spatial direction, which shows significant improvement over previous studies. We have tested the very low dependence on the position of the cavity support points, in order to establish that our designs eliminate the need for fine tuning to achieve extremely low vibration sensitivity. Relative frequency measurements show that at least one of the stabilized lasers has a stability better than 5.6e-16 at 1 second, which is the best result obtained for this length of cavity.
We use the three-cornered-hat method to evaluate the absolute frequency stabilities of three different ultrastable reference cavities, one of which has a vibration-insensitive design that does not even require vibration isolation. An Nd:YAG laser and
a diode laser are implemented as light sources. We observe $sim1$ Hz beat note linewidths between all three cavities. The measurement demonstrates that the vibration-insensitive cavity has a good frequency stability over the entire measurement time from 100 $mu$s to 200 s. An absolute, correlation-removed Allan deviation of $1.4times10^{-15}$ at 1 s of this cavity is obtained, giving a frequency uncertainty of only 0.44 Hz.
We present a tabletop six-axis vibration isolation system, compatible with Ultra-High Vacuum (UHV), which is actively damped and provides 25 dB of isolation at 10 Hz and 65 dB at 100 Hz. While this isolation platform has been primarily designed to su
pport optics in the Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors, it is suitable for a variety of applications. The system has been engineered to facilitate the construction and assembly process, while minimizing cost. The platform provides passive isolation for six degrees of freedom using a combination of vertical springs and horizontal pendula. It is instrumented with voice-coil actuators and optical shadow sensors to damp the resonances. All materials are compatible with stringent vacuum requirements. Thanks to its architecture, the systems footprint can be adapted to meet spatial requirements, while maximizing the dimensions of the optical table. Three units are currently operating for LIGO. We present the design of the system, controls principle, and experimental results.
We describe the angular sensing and control of the 4 km detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO). The culmination of first generation LIGO detectors, Enhanced LIGO operated between 2009 and 2010 with about 40 kW of
laser power in the arm cavities. In this regime, radiation pressure effects are significant and induce instabilities in the angular opto-mechanical transfer functions. Here we present and motivate the angular sensing and control (ASC) design in this extreme case and present the results of its implementation in Enhanced LIGO. Highlights of the ASC performance are: successful control of opto-mechanical torsional modes, relative mirror motions of 1x10^{-7} rad rms, and limited impact on in-band strain sensitivity.
The measurement of extremely small displacements is of utmost importance, both for fundamental studies [1-4], and practical applications [5-7]. One way to estimate a small displacement is to measure the Doppler shift generated in light reflected off
an object moving with a known periodic frequency. This remote sensing technique converts a displacement measurement into a frequency measurement, and has been considerably successful [8-14]. The displacement sensitivity of this technique is limited by the Doppler frequency noise floor and by the velocity of the moving object. Other primary limitations are hours of integration time [12,13] and optimal operation only in a narrow Doppler frequency range. Here we show a sensitive device capable of measuring $mu$Hz/$sqrt{text{Hz}}$ Doppler frequency shifts corresponding to tens of fm displacements for a mirror oscillating at 2 Hz. While the Doppler shift measured is comparable to other techniques [12.13], the position sensitivity is orders of magnitude better, and operates over several orders of magnitude of Doppler frequency range. In addition, unlike other techniques which often rely on interferometric methods, our device is phase insensitive, making it unusually robust to noise.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
