Watt-level Nanosecond 589 nm Source by SHG of a Cascaded Raman Amplifier

Nonlinear Frequency Generation and Conversion: Materials and Devices XX

Chandran

Battle

et al. 2021

We report a CdSiP 2 (CSP) based seeded optical parametric generator (OPG), emitting sub-nanosecond duration, 3 MHz repetition rate, wavelength tunable mid-infrared (MIR) light at 4.2-4.6 µm. We generate up to 0.25 W at 4.2 µm with a total pump conversion efficiency of 42%. The OPG is pumped by a 1.24 µm Raman fiber amplifier system. This is the first demonstration of pumping CSP with a Raman fiber source in this region, and we show that Raman fiber sources in the near-infrared (NIR) are ideal pump sources for non-critically phasematched (NCPM) CSP devices. Pumping CSP at 1.24 µm permits the use of NCPM whilst decreasing the negative effects of both two-photon absorption and linear absorption losses, when compared to conventional 1 µm pumping. This offers a potential advantage for MIR power scaling of CSP parametric devices due to a reduced thermal load in the crystal from residual pump absorption. The OPG is seeded with a continuous-wave fiber supercontinuum source emitting radiation in the 1.7 µm region, to lower the threshold pump intensity required for efficient conversion. NCPM and temperature tuning of the crystal allow for simple wavelength tuning of the idler radiation. We report on laser damage induced by elevated crystal temperatures, which we propose is linked to the decrease in CSP bandgap energy with increasing temperature.

Section: Stimulated Raman Scattering In Optical Fibersmentioning

confidence: 85%

Seeded optical parametric generation in CdSiP2 pumped by a nanosecond pulsed, MHz repetition rate Raman fiber amplifier at 1.24 µm

Nonlinear Frequency Generation and Conversion: Materials and Devices XX

Chandran

Battle

et al. 2021

“…The main drawback of synchronously pumped Raman lasers is that the pump repetition rate needs to be precisely tuned to the Raman cavity length, thereby precluding repetition rate adjustment and pulse-duration tunability. To overcome this limitation, in our recent works we used narrow linewidth continuous-wave (CW) signals to seed Raman amplifiers that were pulse-pumped using Yb:fiber MOPA systems [30]- [32].…”

Section: Seeded Raman Amplificationmentioning

confidence: 99%

“…In [32], we extended the CW seeded, pulsed-pumped Raman amplifier concept to the second Stokes shift at 1179 nm by using a cascaded Raman amplifier architecture. The 1120 nm output of a CW-seeded Raman amplifier (pulse-pumped by a Yb:fiber MOPA system) was used to pulse-pump a second Raman amplifier stage that was seeded by a CW signal at 1179 nm from a DFB laser diode.…”

Section: Seeded Raman Amplificationmentioning

confidence: 99%

Visible Raman-Shifted Fiber Lasers for Biophotonic Applications

Runcorn

Görlitz

IEEE J. Select. Topics Quantum Electron.

et al. 2018

The efficient nonlinear conversion of Yb-doped fiber laser systems using a combination of stimulated Raman scattering and second-harmonic generation is an effective method for developing sources for biophotonic applications in the yellowgreen spectral region. In this paper, we review recent progress in the development of these sources, compare the relative benefits of differing source architectures and demonstrate STED microscopy using an exemplar source.

“…In our previous works, we have shown that Raman amplifiers pulse-pumped by Yb:fiber master oscillator power amplifier (MOPA) systems, seeded with narrow linewidth CW signals, followed by frequency-doubling in periodically poled crystals are an effective route to generating yellow-green pulses [3][4][5]. The use of a discreet Raman amplifier, however, has an impact on the power-scaling potential due to the insertion loss of the components and deleterious nonlinear effects in the Raman amplifier fiber.…”

Section: Introductionmentioning

confidence: 99%

Microjoule Nanosecond 560 nm Source by SHG of a Combined Yb-Raman Fiber Amplifier

Runcorn

Laser Congress 2017 (ASSL, LAC)

Taylor

2017

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