"Russian Technological Association Ltd" presents the UV laser galvanometric scanner

Model RTA-GS-01

The operation principle of the UV laser scanner model RTA-GS-01 (Photo 1) is based on the Galvanometric Scanning (GS) technology that allows wide-angle, fast programmable deflecting of a Ultra-Violet (UV), visible, or IR laser beam in any desirable direction. The particular configuration of the instrument described here is customized as programmable UV scanner combining an UV laser equipped with acoustic-optical Q-switch, a GS scanner and high-quality UV optics. It permits tightly controllable UV irradiation of any chosen spot on a variable-size sample.

In many cases controllable scanning of a focused laser beam on some surface is required. It could be material processing (laser cutting and welding), or diagnostics.

There are a few available laser beam scanning technologies based on:

For the application, which not requires extremely fast scanning, an optical-mechanical scanner is preferable. Moreover, optical-mechanical scanners can easily deflect variety of wavelengths (depend only on the mirror coating). The most popular optical-mechanical scanners are based on galvanometer scanner technology – electromagnet actuators with beam-deflecting mirrors attached on the top of actuator’s rotor. From the list of the problems specific for this technology the most serious is the repeatability of pixel positioning caused by mechanical inertia of the actuator. Because of this, the calibrating system was introduced into the system. The key element of this calibrating system is the optical angular sensor that provides close-loop control of the deflection angle. RTA-GS-01 scanner utilizes two-dimensional defection head based on upgraded CT 6210 deflectors (from Cambridge Technology) equipped with 266-nm mirrors.

The scanner electronics and software allows writing a pattern of variable exposure on a sample according to the drawing performed in Bitmap compatible format.

The built-in air-cooled DPSS pulse-periodic UV laser (266-nm) can be used both for the system adjustment and sample irradiation. Use of an external pulse-periodic or CW laser is also possible.

The scanner can be upgraded and used in a programmable scanning mode for a variety of applications. The design also allows transforming it into an UV confocal microscope by installing additional hardware and the corresponding software.

Therefore, the scanner has to be frequency-synchronized with the built-in pulse-periodic laser, so the laser pulse (20-ns duration) can be positioned on any choused spot (pixel) of the sample producing micron-size exposed pixel. Also, the attenuator/modulator controls the energy of the laser beam at the pixel.

The scanner contains the following elements, which, except the controlling computer and laser power supply, are combined in the single unit (Photo 2).