Tuesday, 18 October 2016

Acousto optic modulator

They are used in lasers for Q-switching, telecommunications for signal modulation, and in spectroscopy for frequency control. Acousto - optic modulators are optical modulators based on the acousto-optic effect in some crystal or glass. Identify the best acousto - optic modulator and RF driver solution.


A Guide to Acousto - Optic Modulators. Within these devices incoming light Bragg diffracts off acoustic wavefronts which propagate .

This can be simple ON:OFF modulation for fast switching or variable level modulation to provide proportional intensity control.

The Brimrose free space Acousto - Optic Modulator (AOM) is used to control laser beam intensity, frequency modulation, frequency shifting, control pulses, switching time, and more.

The AOMs are offered with conduction and water cooled enclosures. TE cooled enclosures are available upon request. A practical problem that arises when using acousto - optic modulators (AOMs) to scan the laser frequency is the dependence of the beam diffraction angle on the modulation frequency. Alignment problems with AOM-modulated laser beams can be effectively eliminated by using the AOM in the double-pass configuration, . APEs Acousto - Optic Modulator AOM modifies the intensity of laser beams, sometimes it is called Bragg Cell. AA Opto-Electronic offers its customers solutions from prototype design to large volume manufacturing thanks to its internal resources : a large range of standard acousto-optic devices are proposed from UV (1nm) to far IR (1 µm).


Basic Acousto Optic Modulator and Driver. The input Bragg angle is given by: θ λ. When the strain is generated by an acoustic compression or rarefaction, an AOM is formed. Because the acoustic signal is sinusoidal, a moving refractive index grating is formed . Modulators ideal for separating pulses internally or externally to laser cavity. Fiber-Q series of industry-leading low-loss fiber-coupled AO modulators . Many of these products are available fibre-coupled. UV Acousto - Optic Modulator ). INTRODUCTION TO ACOUSTO - OPTIC MODULATORS AND DEFLECTORS: Acousto-optic components are typically used internal or external to laser equipment for the electronic control of the intensity (modulation) and or position ( deflection) of the laser beam.


Interaction of acoustic waves and light occur in optical . The isolation can, in principle, be perfect while the noise reduction can be significant up to about 1kHz and as large as dB at low frequency. Fourier mode coupling theory was first employed in the spectral analysis of several nonuniform fiber Bragg grating (FBG)-based acousto - optic modulators ( NU-FBG-AOMs) with the effects of Gaussian-apodization (GA), phase shift (PS), and linear chirp (LC). Because of the accuracy and simplicity of the algorithm applied in . The rise time of the modulator is simply deduced by the necessary time for the acoustic wave to travel through the laser beam. For highest speeds the laser beam will . So the acousto - optic device is modulating the output along the Bragg diffraction angle, switching it on and off. A fun experiment transmitting sound waves via modulated laser light.


The most common type is an acousto - optic modulator. The transmission losses through some crystal or glass piece are small as long as the acoustic wave is switched off, whereas strong Bragg reflection occurs with the acoustic wave switched on, so that the losses are typically of the order of per pass, corresponding to .

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