Passive alignment stability and auto-alignment of multipass amplifiers based on Fourier transforms

Schuhmann, Karsten; Kirch, K.; Knecht, A.; Marszałek, Mirosław; Nez, F.; Nuber, J.; Pohl, Randolf; Schulthess, Ivo; Sinkunaite, Laura; Zeyen, Manuel; Antognini, Aldo

doi:10.1364/ao.58.002904

“…While purely FT based amplifier designs are well known to deliver high-quality beams [16,27], the addition of a 4f-stage to such a multipass amplifier is new and provides several advantages. For example, as mentioned, our multipass amplifier design requires on average only one array mirror per pass over the disk thanks to the 4f-stage.…”

Section: Experimental Realizationmentioning

confidence: 99%

A compact 20-pass thin-disk multipass amplifier stable against thermal lensing effects and delivering 330 mJ pulses with M² < 1.17

Zeyen,

Affolter,

Ahmed

et al. 2023

Preprint

0

View full text Add to dashboard Cite

We report on an Yb:YAG thin-disk multipass amplifier delivering 50 ns long pulses at a central wavelength of 1030 nm with an energy of 330 mJ at a repetition rate of 100 Hz. The beam quality factor at the maximum energy was measured to be M² = 1.17. The small signal gain is 20, and the gain at 330 mJ was measured to be 6.9. The 20-pass amplifier is designed as a concatenation of stable resonator segments in which the beam is alternately Fourier transformed and relay-imaged back to the disk by a 4f-imaging optical scheme stage. The Fourier transform propagation makes the output beam robust against spherical phase front distortions, while the 4f-stage is used to compensate the thermal lens of the thin-disk and to reduce the footprint of the amplifier.

show abstract

“…While purely FT based amplifier designs are well known to deliver high-quality beams [16,27], the addition of a 4f-stage to such a multipass amplifier is new and provides several advantages. For example, as mentioned, our multipass amplifier design requires on average only one array mirror per pass over the disk thanks to the 4f-stage.…”

Section: Experimental Realizationmentioning

confidence: 99%

A compact 20-pass thin-disk multipass amplifier stable against thermal lensing effects and delivering 330 mJ pulses with M² < 1.17

Zeyen,

Affolter,

Ahmed

et al. 2023

Preprint

0

View full text Add to dashboard Cite

We report on an Yb:YAG thin-disk multipass amplifier delivering 50 ns long pulses at a central wavelength of 1030 nm with an energy of 330 mJ at a repetition rate of 100 Hz. The beam quality factor at the maximum energy was measured to be M² = 1.17. The small signal gain is 20, and the gain at 330 mJ was measured to be 6.9. The 20-pass amplifier is designed as a concatenation of stable resonator segments in which the beam is alternately Fourier transformed and relay-imaged back to the disk by a 4f-imaging optical scheme stage. The Fourier transform propagation makes the output beam robust against spherical phase front distortions, while the 4f-stage is used to compensate the thermal lens of the thin-disk and to reduce the footprint of the amplifier.

show abstract

“…Thus, the vibrationbased methods are the most suitable for identification the misalignment faults of aero-engine dual-rotor. Up to now, many vibration-based methods have been proposed, such as Fourier Transform (FFT) [11,12], Wavelet Transform (WT) [13][14][15], Hilbert Huang Transform (HHT) [16,17], Empirical Mode Decomposition (EMD) [18,19]. Many classifiers such as neural network (NN) [20], support vector machine (SVM) [21], fuzzy logic (FL) [15,22].…”

Section: Introductionmentioning

confidence: 99%

Dual-rotor misalignment fault quantitative identification based on DBN and improved D-S evidence theory

Yang

¹

,

Fanyu

²

,

Miao

³

et al. 2021

Mechanics & Industry

View full text Add to dashboard Cite

Misalignment fault is the main factor that affects the normal running of dual-rotor system. Quantitative identification the misalignment fault is an important way to ensure the safe and stable service of the dual-rotor system, while the identification accuracy of traditional methods is low. Aiming at the above problems, this paper proposed a dual-rotor misalignment fault quantitative identification method based on DBN and D-S evidence theory improved by mutual information measure (MIMD-S). Seven groups experiments were conducted and several vibration signals were collected. By comparing it with the traditional methods D-S, and Pignistic improved D-S (PD-S) evidence theory, the results show that the method proposed in this paper improves the accuracy of the misalignment fault quantitative identification of the dual-rotor, the identification error rate was only 0.36%.

show abstract

Passive alignment stability and auto-alignment of multipass amplifiers based on Fourier transforms

Cited by 4 publications

References 22 publications

A compact 20-pass thin-disk multipass amplifier stable against thermal lensing effects and delivering 330 mJ pulses with M² < 1.17

A compact 20-pass thin-disk multipass amplifier stable against thermal lensing effects and delivering 330 mJ pulses with M² < 1.17

A compact 20-pass thin-disk multipass amplifier stable against thermal lensing effects and delivering 330 mJ pulses with M² < 1.17

Dual-rotor misalignment fault quantitative identification based on DBN and improved D-S evidence theory

Contact Info

Product

Resources

About