Piezo-optical modulators

The Production and Properties of Polarized Light Piezo-Optical Modulators Practical Chiral Detectors... 

Fig. 1 Setup for transient holographic grating measurements. The electro-optic modulators (EOMs) are used for 180°-phase shifts of the holographic grating. The piezo mirror serves for phase matching between the diffracted beam and the coherent reference wave generated by the local oscillator. The setup is a modified version of the one described in [87]...

Mechanical engineers have used polarized light to detect stress patterns for many years and more recently a number of workers [3-6] have explored the possibilities of photoelasticity for the fabrication of polarization modulators. The systems have been given several names, photoacoustic modulators, photoelastic modulators and stress modulators, the term photoelastic modulator will be used in this chapter. There are basically two types of photoelastic modulator, composite resonators and matched element resonators. Diagrams of the composite resonator and matched element resonator are shown in figures 6 and 7 respectively. The original piezo-optical devices [7] were composite resonators composed of a central block of optical... 

EBIT as shown in Fig. 2. The trapped Si + ions will lie at the laser beam waist within the enhancement cavity, and to keep the finesse of the cavity as high as possible it is necessary for the high reflectivity mirrors to lie within the EBIT vacnnm chamber. The Ti sapphire laser will be locked to the high finesse cavity nsing the rf sideband locking techniqne [33]. Fast frequency fluctuations will be corrected using an acousto-optic modulator in a double-pass configuration, whilst the slower branch of the servo loop will use a piezo-mounted mirror in the laser cavity. 

Such piezo-electric modulation is useful for devices such as polarimeters and spectrometers where one wishes to study optical phenomenon as a frmction of polarization. 

The application of interference techniques overcomes the limitations exerted by the large optical wavelengths. With commercial phase-measurement interference microscopes (PMIM), a surface resolution of the order of 0.6 nm can be achieved [33, 34]. In a microscope a laser beam is both reflected from the sample surface and from a semitransparent smooth reference surface (Fig. 3). The interference pattern is recorded on an area detector and modulated via the piezo-electric driven reference surface. The modulated interference pattern is fed into a computer to generate a two-dimensional phase map which is converted into a height level contour map of the sample surface. While the lateral resolution (typically of the... 

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