scholarly journals Quantum Noise in a Fabry-Perot Interferometer Including the Influence of Diffraction Loss of Light

Galaxies ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 9
Author(s):  
Shoki Iwaguchi ◽  
Tomohiro Ishikawa ◽  
Masaki Ando ◽  
Yuta Michimura ◽  
Kentaro Komori ◽  
...  
Keyword(s):  
Gravitational Waves ◽  
Quantum Noise ◽  
Higher Order ◽  
Diffraction Loss ◽  
Optical Cavities ◽  
Higher Order Modes ◽  
Fabry Perot ◽  
Primordial Gravitational Waves ◽  
Mode Loss ◽  
High Finesse

The DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is designed to detect gravitational waves at frequencies between 0.1 and 10 Hz. In this frequency band, one of the most important science targets is the detection of primordial gravitational waves. DECIGO plans to use a space interferometer with optical cavities to increase its sensitivity. For evaluating its sensitivity, diffraction of the laser light has to be adequately considered. There are two kinds of diffraction loss: leakage loss outside the mirror and higher-order mode loss. These effects are treated differently inside and outside of the Fabry-Perot (FP) cavity. We estimated them under the conditions that the FP cavity has a relatively high finesse and the higher-order modes do not resonate. As a result, we found that the effects can be represented as a reduction of the effective finesse of the cavity with regard to quantum noise. This result is useful for optimization of the design of DECIGO. This method is also applicable to any FP cavities with a relatively small beam cut and the finesse sufficiently higher than 1.

scholarly journals Design of large mode area all-solid anti-resonant fiber for high-power lasers

2021 ◽  
Vol 9 ◽  
Author(s):  
Xin Zhang ◽  
Shoufei Gao ◽  
Yingying Wang ◽  
Wei Ding ◽  
Pu Wang
Keyword(s):  
High Power ◽  
Single Mode ◽  
Higher Order ◽  
Coupling Scheme ◽  
Resonant Coupling ◽  
Higher Order Modes ◽  
Mode Loss ◽  
Fiber Mode ◽  
Power Needs ◽  
Mode Area

Abstract High-power fiber lasers have experienced a dramatic development over the last decade. Further increasing the output power needs an upscaling of the fiber mode area, while maintaining a single-mode output. Here, we propose an all-solid anti-resonant fiber (ARF) structure, which ensures single-mode operation in broadband by resonantly coupling higher-order modes into the cladding. A series of fibers with core sizes ranging from 40 to 100 μm are proposed exhibiting maximum mode area exceeding 5000 μm2. Numerical simulations show this resonant coupling scheme provides a higher-order mode (mainly TE01, TM01, and HE21) suppression ratio of more than 20 dB, while keeping the fundamental mode loss lower than 1 dB/m. The proposed structure also exhibits high tolerance for core index depression.

Resonant modes of optical cavities with phase conjugate mirrors: higher-order modes

1980 ◽  
Vol 19 (4) ◽  
pp. 479 ◽  
Author(s):  
Pierre-A. Bélanger ◽  
Amos Hardy ◽  
A. E. Siegman
Keyword(s):  
Higher Order ◽  
Phase Conjugate ◽  
Optical Cavities ◽  
Higher Order Modes ◽  
Resonant Modes

scholarly journals Current status of space gravitational wave antenna DECIGO and B-DECIGO

2021 ◽  
Author(s):  
Seiji Kawamura ◽  
Masaki Ando ◽  
Naoki Seto ◽  
Shuichi Sato ◽  
Mitsuru Musha ◽  
...  
Keyword(s):  
Gravitational Wave ◽  
Gravitational Waves ◽  
Space Mission ◽  
Current Status ◽  
Fabry Perot ◽  
Primordial Gravitational Waves ◽  
Expansion Of The Universe ◽  
Black Hole Binary ◽  
Scientific Results ◽  
The Universe

Abstract Deci-hertz Interferometer Gravitational Wave Observatory (DECIGO) is the future Japanese space mission with a frequency band of 0.1 Hz to 10 Hz. DECIGO aims at the detection of primordial gravitational waves, which could be produced during the inflationary period right after the birth of the universe. There are many other scientific objectives of DECIGO, including the direct measurement of the acceleration of the expansion of the universe, and reliable and accurate predictions of the timing and locations of neutron star/black hole binary coalescences. DECIGO consists of four clusters of observatories placed in the heliocentric orbit. Each cluster consists of three spacecraft, which form three Fabry-Perot Michelson interferometers with an arm length of 1,000 km. Three clusters of DECIGO will be placed far from each other, and the fourth cluster will be placed in the same position as one of the three clusters to obtain the correlation signals for the detection of the primordial gravitational waves. We plan to launch B-DECIGO, which is a scientific pathfinder of DECIGO, before DECIGO in the 2030s to demonstrate the technologies required for DECIGO, as well as to obtain fruitful scientific results to further expand the multi-messenger astronomy.

scholarly journals Electrical characterisation of higher order spin wave modes in vortex-based magnetic tunnel junctions

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Alex. S. Jenkins ◽  
Lara San Emeterio Alvarez ◽  
Samh Memshawy ◽  
Paolo Bortolotti ◽  
Vincent Cros ◽  
...  
Keyword(s):  
Spin Wave ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Higher Order ◽  
Spin Torque ◽  
Micromagnetic Simulations ◽  
Higher Order Modes ◽  
Spin Diode ◽  
Super High Frequency ◽  
Wave Modes

AbstractNiFe-based vortex spin-torque nano-oscillators (STNO) have been shown to be rich dynamic systems which can operate as efficient frequency generators and detectors, but with a limitation in frequency determined by the gyrotropic frequency, typically sub-GHz. In this report, we present a detailed analysis of the nature of the higher order spin wave modes which exist in the Super High Frequency range (3–30 GHz). This is achieved via micromagnetic simulations and electrical characterisation in magnetic tunnel junctions, both directly via the spin-diode effect and indirectly via the measurement of the coupling with the gyrotropic critical current. The excitation mechanism and spatial profile of the modes are shown to have a complex dependence on the vortex core position. Additionally, the inter-mode coupling between the fundamental gyrotropic mode and the higher order modes is shown to reduce or enhance the effective damping depending upon the sense of propagation of the confined spin wave.

scholarly journals Small-Sized Interferometer with Fabry–Perot Resonators for Gravitational Wave Detection

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1877
Author(s):  
Nikolai Petrov ◽  
Vladislav Pustovoit
Keyword(s):  
Correlation Function ◽  
Gravitational Waves ◽  
Laser Interferometer ◽  
Zero Order ◽  
Wave Detection ◽  
Resonant Modes ◽  
Fabry Perot ◽  
Spatially Distributed ◽  
Wave Laser ◽  
Higher Sensitivity

It is highly desirable to have a compact laser interferometer for detecting gravitational waves. Here, a small-sized tabletop laser interferometer with Fabry–Perot resonators consisting of two spatially distributed “mirrors” for detecting gravitational waves is proposed. It is shown that the spectral resolution of 10−23 cm−1 can be achieved at a distance between mirrors of only 1–3 m. The influence of light absorption in crystals on the limiting resolution of such resonators is also studied. A higher sensitivity of the interferometer to shorter-wave laser radiation is shown. A method for detecting gravitational waves is proposed based on the measurement of the correlation function of the radiation intensities of non-zero-order resonant modes from the two arms of the Mach–Zehnder interferometer.

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