B. Schulz

Stabilized lasers for advanced gravitational wave detectors

Second generation gravitational wave detectors require high power lasers with more than 100 W of output power and with very low temporal and spatial fluctuations. To achieve the demanding stability levels required, low noise techniques and adequate control actuators have to be part of the high power laser design. In addition feedback control and passive noise filtering is used to reduce the fluctuations in the so-called prestabilized laser system (PSL). In this paper, we discuss the design of a 200 W PSL which is under development for the Advanced LIGO gravitational wave detector and will present the first results. The PSL noise requirements for advanced gravitational wave detectors will be discussed in general and the stabilization scheme proposed for the Advanced LIGO PSL will be described.

Fundamental mode, single-frequency laser amplifier for gravitational wave detectors

An amplifier design for efficient amplification of linearly polarized fundamental mode lasers is presented. The concept was verified by amplifying single-frequency input powers from 1 W to 20 W into output power ranges of 35 W up to 65 W. Beam quality measurements with a mode-analyzer cavity showed only minor beam quality degradation due to the amplification process.

Multipass OPCPA system at 100 kHz pumped by a CPA-free solid-state amplifier.

We present a compact few-cycle 100 kHz OPCPA system pumped by a CPA-free picosecond Nd:YVO4 solid-state amplifier with all-optical synchronization to an ultra-broadband Ti:sapphire oscillator. This pump approach shows an exceptional conversion rate into the second harmonic of almost 78%. Efficient parametric amplification was realized by a two stage double-pass scheme with following chirped mirror compressor. The amount of superfluorescence was measured by an optical cross-correlation. Pulses with a duration of 8.7 fs at energies of 18 µJ are demonstrated. Due to the peak power of 1.26 GW, this simple OPCPA approach forms an ideal high repetition rate driving source for high-order harmonic generation.

Single frequency solid state laser amplifier system: Towards 3 rd generation of gravitational wave detectors

We demonstrate a robust, single frequency, solid state laser amplifier system with 177 W linearly polarized output and 83.5% TEM00 mode content. This power scaling approach is promising for the 3rd generation gravitational wave detectors.

High Power End-Pumped Nd:YVO4 Amplifier

An end-pumped Nd:YVO4-amplifier for efficient amplification of laser sources at 1064 nm will be presented with an optical efficiency > 37%. With an input of 12 W an output power of 47.2 W was achieved.

Nd:YLF Laser Pumped at 880 nm

We present a Nd:YLF Laser pumped directly into the emitting level at 880nm. Using a short pump-fiber maintained linear polarization of the pump-diode. The laser emitted 9.5W at fundamental mode with 63% optical-to-optical efficiency.

Mode discrimination in injection locked high-power single-frequency lasers

We present an injection locked single-frequency laser with an asymmetric resonator for transversal mode control. To characterize the laser at the operation point the TEM00 mode content was measured in respect to the pump power.