Photon Lines UK

Optical Components

AO Polychromatic Modulators

The AOTF.nC is a special acousto-optic tunable filter which uses the anisotropic interaction inside a tellurium dioxide crystal to control independently or simultaneously different lines from an incoming UV or VISIBLE laser light (White laser, Ar+, Kr+, HeNe,DPSS, Dye...). Up to 8 distinct lines can be mixed and separately modulated in order to generate different colorimetric patterns.

The specific crystal cut of the AOTF.nC produces good diffraction efficiency (> 90%), narrow resolution (1-2 nm), a low cross-talk between lines, and high extinction ratio. The large separation angle between 0 and 1st orders, as well as the excellent output chromatic colinearity (<0.2 to <0.3 mrd ) make this AOTF a powerful tool for free space or fiber pigtailed applications. Its associated thermal stabilisation maintains stable diffraction efficiency and reduces dramatically beam drift with single mode fiber pigtailing. This is a major advantage for high sensitivity applications

 The associated driver MDSnC, based on DDS (Direct Digital Synthesizer), has been specially designed in order to exploit the best of the AOTF.nC features. Its compact design with single power supply, low RF emissions and ease of use will satisfy the most demanding of applications, where accuracy and flexibility are key requirements.

Thanks to its complete digital design and integrated microcontroller, setting up is fast, simple and repeatable. Access to and adjustments of functions is simple with either a bright LCD display (with remote control adjustment) or through a RS232 serial link (with computer control) or USB communication. All parameters are stored in an EEPROM and are automatically loaded after each switch on.

Each line is externally controlled by a distinct modulation input signal which can be TTL or analog. Additionally, all lines can be simultaneously controlled by a blanking signal which produces smooth effects without modifying the colorimetric balance. The combination of the modulation input and blanking signals provides the best extinction ratio performance (> 100 dB).