Electro-optic signal

After the switching off of the electric field, the electro-optical signal decays exponentially with time t, and this decay is simply related to the particle geometry [46] ... 

Decay of the Electro-Optical Signal. After switching off the electrical field the electro-optical signal t decays exponentially with time (2) ... 

Circular dichroism employs standard dispersive or interferometric instmmentation, but uses a thermal source that is rapidly modulated between circular polari2ation states using a photoelastic or electro-optic modulator. Using phase-sensitive detection, a difference signal proportional to the absorption difference between left- and right-polari2ed light, AA is recorded as a function of wavenumber. Relative differential absorptions... 

M. M. Fejer. Quasi-phasematched for fiequency conversion and all optical signal processing (short course 1260) in Conference on Lasers and Electro-Optics, Baltimore (2001). 

Ashkin and Dziedzic (1977) used the radiation pressure force of a laser beam to levitate microdroplets with the apparatus presented in Fig. 15. A polarized and electro-optically modulated laser beam illuminated the particle from below. The vertical position of the particle was detected using the lens and split photodiode system shown. When the particle moved up or down a difference signal was generated then a voltage proportional to the difference and its derivative were added, and the summed signal used to control an electro-optic modulator to alter the laser beam intensity. Derivative control serves to damp particle oscillations, while the proportional control maintains the particle at the null point. 

Electro-optic modulation (Pockels effect) using a poled polymer is shown schematically in Figure 5.33, where an optical signal confined in a wave-guide is modulated by the application of an external voltage, known as a Mach-Zender Interferometer. 

Acousto-Optic Signal Processing Theory and Implementation, edited by Norman J. Berg and John N. Lee Electro-Optic and Acousto-Optic Scanning and Deflection, Milton Gottlieb, Clive L. M. Ireland, and John Martin Ley Single-Mode Fiber Optics Principles and Applications,... 

The module further comprises a flat end surface 124 to which a substrate 126 may be bonded. The substrate is of alumina or sapphire and has disposed thereon a mosaic array 3 of electro-optical detectors 4. The detectors are formed by etching or laser cutting of a mercury cadmium telluride layer which has been deposited on the substrate. Each detector is connected at one end 130 to a common reference terminal 132 and at the other end 136 to terminal 134. The substrate further comprises a pattern of through holes 138 and metal dots 140 such that each signal terminal 134 contacts a dot 140. The substrate 126 is aligned on the end surface 124 such that the metal dots 140 in each hole 138 contacts a conductor 114. As a result, each detector 4 is coupled to a pad 118. 

PLZT in thin and thick film form can be exploited for a variety of applications including optical signal switching and modulation. An attraction of PLZT is its high electro-optic coefficient and in consequence low drive voltages to perform a particular function (c.f Table 8.1). The PLZT thin film switch described below is included to illustrate principles rather than because of very significant commercial importance. 

Fig. 1. Set-up of the PTB laser system. The Nd YAG laser is frequency stabilized onto a selected iodine absorption line using the phase modulation method. The probe beam is modulated at 2.05 MHz by an electro-optic modulator (EOM), the pumb beam is frequency shifted by an acousto-optical modulator (AOM). The driving AOM rf power is chopped in order to cancel frequency offsets introduced by the Doppler background using a lock-in detection scheme. The transmitted probe beam signal is detected by a photodiode (PD) and mixed with the EOM rf in a double balanced mixer (DBM)...

Jimenez D, Martfnez-M nez R, Sancendn F, Soto J. Electro-optical triple-channel sensing of metal cations via multiple signalling patterns. Tetrahedron Lett 2004 45 1257-9. 

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