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Johann Gabriel Meyer

Publications and source records attributed to Johann Gabriel Meyer.

4 recordsLinked to original sources

Low peak-power pulse compression in gas-filled Herriott cells in the 2 μm wavelength range

At laser wavelengths longer than the prominent 1 μm range of high-power ytterbium-doped lasers, nonlinear phase shifts produced in nonlinear media for spectral broadening and subsequent pulse compression decrease drastically. Consequently, at the 2 μm wavelength range, the threshold of the applicable peak power for pulse compression in gas-filled multipass cells increases. The common approach of choosing a Herriott multipass cell configuration close to the concentric resonator does not necessarily lead to the highest total nonlinear phase shift, due to a restriction of the total number of reflections on the cell mirrors of a given size. Therefore, an analytical approach is presented here to maximize the nonlinear phase shift for a given set of mirrors, considering lossless and dispersionless propagation. Furthermore, to achieve pulse compression with gas-filled multipass cells for relatively low peak powers at wavelengths around 2 μm, we developed a high-pressure gas cell and demonstrated experimentally pulse compression in the negative- and positive dispersion regimes, with achieved pulse durations of around 40 fs and 55 fs respectively.

physics.optics↗

Carrier-Envelope-Offset Frequency Stabilization of a High Peak and Average Power Thin-Disk Oscillator

In this work, we demonstrate carrier-envelope-offset (CEO) frequency stabilization of a Kerr-lens mode-locked thin-disk oscillator delivering 180 W average power, 80 MW output peak power, and >500 MW intra-cavity peak power, the highest peak power achieved in any stabilized thin-disk oscillator system. The CEO frequency detection is performed with an f-2f interferometer based on supercontinuum generation in a YAG crystal. Intra-cavity loss modulation using an acousto-optic modulator, that simultaneously provides the Kerr lens, yields 50 mrad of residual phase noise with a 250 kHz control bandwidth. After pulse compression to 0.9 GW peak power in a dual-stage multipass cell, the system directly enables high harmonic generation in noble gases. These results represent a significant step in realizing a compact and robust high-repetition-rate driver system suitable for vacuum ultraviolet and extreme ultraviolet frequency comb generation.

physics.optics↗

Quasi-waveguide amplifiers based on bulk laser gain media in Herriott-type multipass cells

We present here a new geometry for laser amplifiers based on bulk gain media. The overlapped seed and pump beams are repetitively refocused into the gain medium with a Herriott-type multipass cell. Similar to a waveguide, this configuration allows for a confined propagation inside the gain medium over much longer lengths than in ordinary single pass bulk amplifiers. Inside the gain medium, the foci appear at separate locations. A proof-of-principle demonstration with Ti:sapphire indicates that this could lead to higher amplification due to a distribution of the thermal load.

physics.optics↗

Multipass Faraday rotators and isolators

Faraday isolators are usually limited to Faraday materials with strong Verdet constants. We present a method to reach the 45° polarization rotation angle needed for optical isolators with materials exhibiting a weak Faraday effect. The Faraday effect is enhanced by passing the incident radiation multiple times through the Faraday medium while the rotation angle accumulates after each pass. Materials having excellent thermos-optical properties in the ultraviolet and mid-infrared range become available for optical isolators. Herriott-type multipass cells offer a simple and compact way to realize the desired propagation length in usual optical materials of standard sizes. A proof-of-principle experiment was carried out, demonstrating polarization rotation of a 532 nm laser beam by an angle of 45° in anti-reflection-coated fused silica surrounded by a standard neodymium ring magnet.

physics.optics↗