Tech Briefs

DPSS UV Source Targets Gas Lasers and Life Sciences

System is designed for applications that relied on pulsed nitrogen gas lasers.

Spectra-Physics Corp., Tucson, Arizona

Nitrogen lasers have been used for more than 15 years in life science and forensic applications and will continue to play a role in many scientific and industrial applications. But researchers, OEMs, and system integrators working on innovative, cutting-edge applications need higher-performance lasers. The Explorer, a diode-pumped solid-state OEM laser system with flexible power and control electronics, is a low-power, actively Q-switched, ultraviolet (UV) laser system that operates at 349 nm for bioinstrumentation applications that in the past have relied on pulsed nitrogen gas lasers.

altBecause it has several key performance advantages compared to nitrogen lasers — such as increased throughput, superior signal-to-noise ratio, and better focus ability — the Explorer is particularly suited for existing and emerging MALDI (Matrix Assisted Laser Desorption and Ionization) and Laser Microdissection applications. The new DPSS UV source has several advantages compared to gas lasers, including compactness, improved lifetime, lower cost of ownership, Gaussian-beam properties, high repetition rates, and increased pulse-to-pulse stability. These characteristics also meet the needs of established as well as future applications in analytical chemistry, genomics, drug development, and forensics.

The main advantages of DPSS-based lasers compared to nitrogen lasers is the better performance, higher repetition rate, and the much improved lifetime of the product. The Explorer can be operated from single-shot up to a 5-kHz pulse rate at variable pulse energies. It uses a proprietary intra-cavity conversion technology for longer lifetimes and higher energy pulses at lower pump powers. The standard pulse energy specifications are either 60 or 120 μJ, and pulse widths of less than 5 ns. The Explorer features the high-peak power that is essential for demanding MALDI and Laser Microdissection applications. In addition, the Explorer provides a TEM00 output beam, which enables tight focusing and high spatial resolution. With a pulse-to-pulse stability of less than 3%, RMS applications will benefit from a significantly reduced signal-to-noise ratio. Unlike nitrogen lasers, no cartridges need to be exchanged, and field service requirements are held to a minimum.

Integrated into the power supply are features such as patent-pending BURST-Mode and First-Pulse Suppression (FPS), both of which eliminate the need for users to provide external timing circuits to control and operate the laser. BURST-Mode enables users to set a specific number of laser pulses (1 to 4,095). This feature allows customers to fire the desired amount of laser pulses without having to provide external real-time operating electronics to monitor and manage laser timing.

Customers can interface with the Explorer power supply either through an RS-232 software interface or via analog TTL control signals. The compact Explorer laser head and power supply support existing triggering schemes for nitrogen lasers, as well as more advanced pulse configurations.

This article was written by Jürgen Niederhofer, Product Manager, at Spectra-Physics GmbH. For more information, contact Mr. Niederhofer at This email address is being protected from spambots. You need JavaScript enabled to view it. .