Stable CW low noise operation of a diode-pumped monolithic laser at 355 nm beyond 30 mW
Oxxius 355 nm UV laser sources today
This 2007 SPIE paper presents the first long-term stability characterization of a 355 nm monolithic CW UV laser based on a quasi-monolithic DPSS architecture — a design that eliminates alignment sensitivity while maintaining the efficiency and compactness required for instrument integration. By systematically optimizing the thermal conditions of each cavity element and monitoring UV power, noise, and spectral behavior, the authors establish the thermal operating window for reliable 30 mW+ CW output at 355 nm.
The quasi-monolithic approach described here — combining compactness, low power consumption, and reduced thermal drift — is the same architectural principle that underpins Oxxius’s production UV laser sources today. The 355 nm wavelength addresses a wide range of demanding applications including flow cytometry, cell sorting, wafer inspection, and micromachining, all of which require both low-noise output and proven long-term reliability. These requirements are met by the LBX-355 and related UV sources currently available in the Oxxius product line.
Abstract
Low noise CW UV lasers are needed for applications in bioinstrumentation (cell sorting, cytometry…) and semiconductors (wafer inspection, micromachining …). We have recently demonstrated that such laser sources can be obtained with diode pumped solid state (DPSS) architectures. One key to success was the quasimonolithic structure of the laser. The advantages of quasi-monolithic DPSS lasers for UV generation are simplicity of design, compactness, efficiency and thus low power requirements and limited heating. In this paper, we present for the first time a long term characterization of the diode pumped CW 355 nm laser. The interplay between pump absorption, cavity length, 1064 mode size, walk-off angle, acceptance angle has been optimized. In our experiments, the temperature of each element of the laser was controlled and UV power, noise and spectra were monitored versus these temperatures. At 2.5 …