Purity and Stability Meet High Power – 100 W Single-Frequency Laser

Introduction

Scientific experiments in fields such as gravitational wave detection, quantum sensing, and atomic physics require laser sources that combine extremely high spectral purity with stable optical power and excellent beam quality. Single-frequency lasers provide the narrow linewidth and coherence necessary for interferometric measurements and quantum control experiments, while high optical power enables improved signal-to-noise performance and increased measurement sensitivity.

As a solution to those challenges, AMS Technologies presents a 100 W single-frequency laser platform developed to meet the demanding requirements of next-generation scientific instrumentations. Developed by the neoLASE team in Hanover, Germany, the system combines narrow linewidth operation, excellent beam quality, and robust power scaling through an optimized master oscillator power amplifier (MOPA) architecture. The result is a highly stable laser source suitable for precision interferometry, quantum technology platforms, and advanced optical metrology.

Motivation

Modern precision experiments rely on laser sources that exhibit exceptional frequency stability, low phase noise, and long-term operational reliability. In gravitational wave interferometers, for example, the sensitivity of the instrument is directly linked to the quality of the laser source used to probe kilometer-scale interferometric arms. Similarly, quantum technologies such as optical clocks, atom interferometers, and quantum sensing systems require highly coherent laser radiation to manipulate and measure atomic or photonic quantum states. Traditional narrow-linewidth lasers typically operate at relatively low optical power. Scaling optical power while preserving low frequency and amplitude noise is therefore a key engineering challenge.

Laser Architecture

The 100 W single-frequency laser platform uses a master oscillator power amplifier (MOPA) architecture based on the proven neoVAN amplifier technology and a Ten64 single-frequency NPRO seeder from VM Photonics. The neoVAN amplifiers are operating worldwide in gravitational wave detectors like LIGO, VIRGO, KAGRA and GEO. The narrow-linewidth seed laser is a new development of VM Photonics with improved noise performances compared to common single-frequency lasers (1). In previous experiments the performance of the neoVAN and Ten64 combination was measured up to 40W of output power (1).

Driven by customer demand, we now demonstrate further power scaling into the 100W class range – while still maintaining the exclusive noise performance and beam quality of the system.

To maintain the excellent beam parameters at high optical power a careful control of thermal and optical effects within the amplifier system is required. The neoVAN platform incorporates advanced thermal management strategies by passively cooled laser crystals and advanced optical packaging technologies. The precision mechanical and optical design further ensure long-term alignment stability and resistance to environmental disturbances. Active monitoring and feedback systems combined with low noise laser electronics stabilize key operational parameters such as temperature, pump- and output power. These measures contribute to reliable long-term operation in laboratory or large-scale research facilities.

Performance Characteristics

The laser platform is designed to meet the requirements of demanding precision measurement systems. To achieve an output power of more than 100W two neoVAN-4S amplifier units are used to scale the 0,4W of seed power into a final output power of 102W. A picture of the beam profile at full power is shown below.

The beam quality factor M² was measured to be below 1.1. An important parameter is the low noise performance of the laser system, measured with 0,17% RMS power noise over a period of 1 hour (see plot below). For active power noise reduction, the system is equipped with a laser diode current shunt that allows fast modulation and therefore a power noise stabilization.

The frequency noise of the amplifiers is almost similar to the NPRO noise and was measured in previous experiments (1,2). Beside the beam quality, the pointing stability is an important factor to couple the laser light into large interferometers or enhancement cavities. The pointing was measured to be less than 12 µrad over a period of 1 hour. Therefore, the systems performance demonstrates all requirements needed for large scale interferometric or highly stable single-frequency laser applications. The footprint of the compact system is 900 x 500 mm and fully incorporates the seed laser and an output telescope.

Summary

High-power single-frequency lasers serve as the primary light source in large-scale interferometers like gravitational wave detectors. Quantum experiments involving cold atoms, optical clocks, and quantum sensors require stable coherent light sources for precise manipulation of quantum states. High-coherence laser sources enable interferometric measurements with extremely high sensitivity. Applications include optical metrology, displacement sensing, and fundamental physics experiments. The developed 100 W single-frequency laser platform demonstrates how advanced optical engineering can meet the demanding requirements of modern scientific instrumentation. By combining scalable optical amplification with robust thermal, optical and mechanical design, the system delivers both high power and exceptional spectral purity. This unique laser platform enables researchers and system integrators to push the limits of high precision experiments.

Are you looking for solutions to push photon manipulation to the technical limits? Contact us to discuss your requirements!

References

1)    H. Vahlbruch , F. Meylahn, B. Willke, “Characterization of non-planar ring oscillators at a wavelength of 1064 nm for high precision metrology”, Rev. Sci. Instrum. 96, 113001 (2025)

2)    N. Bode, F. Meylahn, and B. Willke, “Sequential high power laser amplifiers for gravitational wave detection,” Opt. Express  28, 29469-29478 (2020).