PowerXP – Compact motorized attenuator

20 Jan 2016

Automated and continuous laser power control is a cost saving function in the list of laser features. Lasers operating in any regime (CW, Q-switching, mode locking) lack this function as the most important laser quality specifications are determined by solutions implemented in the laser cavity. Most of the laser manufacturers do not integrate extra-cavity continuous attenuation solutions in their lasers, as continuous power control is not required for every application.

PowerXP is an extra-cavity attenuator, which provides continuous laser output power control in wide dynamic range allowing manipulation of transmitted power from 0.04% to 99%. To push spectral performance to the boundaries a combination of zero order half-wave phase retardation plate and high contrast Brewster thin film polarizer produced by IBS coating technology is being used.

The operation principle of the attenuator is quite simple – λ/2 phase retardation plate rotates the polarization of an incident beam, which then passes onto the polarizer where orthogonal polarizations S and P are separated into two separate S and P polarized beams. Intensity ratio between the two beams is controlled by rotating the waveplate without alteration of other beam/pulse parameters. Both S and P polarized beams can be used after using the attenuator, but detachable beam dump for S polarized beam is default for user convenience.

The motor of the attenuator is driven by stepper controller that provides 6400 micro-steps between minimum and maximum attenuation – which stands for the resolution of <0.02% per micro-step in laser power control. It is convenient to control the attenuator both via computer or using buttons on the controller at any time.

Despite continuous attenuation, industrial applications require power manipulation at high rates. With PowerXP it takes only 1 second to switch between MIN and MAX attenuation. External attenuator adds extra dimensions to the laser device, but being the smallest polarization control based attenuator PowerXP can be easily integrated into a laser or laser system.

Specifications: