Fiber optic phase modulator

PVDF is useful for a variety of measurement instruments iitcluding acceletometers, stress gauges, strain gauges, shock gauges, turbulence sensors, fiber optic phase modulators. 

A fiber optic phase modulator using a PVDF-VDFATE copolymer to jacket an optical fiber has been designed [43]. Figure 27 shows a sdrenutic view the configuration. 

Figure 27 Cross-sectional view of fiber optic phase modulator ieaoiting PVDF attached onto a glaa epoxy substrate. (Adapted from Ref. O.)...

M. Imai, T. Yano, Y. Ohtsuka, K. Moioi. and A. Od ima, Wide-6e< aeacy fiber-optic phase modulator using piezoelectric polymer coating. IEEE Photonics Techno Lett. 2 727-729 (1990). 

Because NL(t) has the same periodicity as A(t) the comb structure of the spectrum, as derived in section 3, is not affected. In an optical fiber self-phase modulation can be quite efficient even though the nonlinear coefficient in fused silica is comparatively small. This is because the fiber core carries a high intensity over an extended length. 

Detailed investigation on the optical characteristics, including the electro-optic phase modulation, electric hysteresis property, and thermo-optic coefficient, of transparent PMN-PT electro-optic ceramics have been conducted [229]. A polarization independent PMNT electro-optic switch by using s -shifted fiber Sagnac interferometer stmcture was constracted and analyzed experimentally. Some switch performances, including thermal characteristic and different switching frequency response, were also realized. 

A. Gusarov, N. H. Ky, H. G. LImberger, R. P. Salathe and G. R. Fox, High-performance optical phase modulation using piezoelectric ZnO-coated standard telecommunication fiber, J. Lightwave Technol., 14 [12], 2771-2777 (1996). 

FIGURE 16 Additive pulse mode-locked laser. The output of the color center laser is coupled to an optical fiber. Self-phase modulation in the fiber adds bandwidth to the pulse, which is coupled back to the laser. The combination produces femtosecond-duration pulses. (OC, output coupler BS, beam splitter BTP, birefringent tuner plate HR, high reflector PZT, piezotransducer). 

This simplified picture of self-phase modulation neglects dispersion, time-delayed nonlinearities and shock formation which is all known to occur in optical fibers. While no in fused silica is at least as fast as a few fs, the GVD broadens the pulses as they travel along the fiber so that the available peak power Pa is decreased. Effective self-phase modulation however takes place when the so called dispersion length is much smaller then the nonlinear length whose ratio is given by [27]... 

Accelab sell a liquid-liquid extraction module based on a fiber-optic sensor for detecting the phase boundary (this module is part of their automated synthesis system, but is also available separately). 

In this paper, we employ a new version of our own fiber-optic-based multifrequency phase and modulation fluorometer. 

Figure 3. Multifrequency phase and modulation plot for 1 uM 2,7-dichlorofluorescein determined with the 10-meter fiber-optic probe. Laser excitation at 457.9 nm and emission monltoced at 520 nm (8 nm bandpass). The recovered lifetime is 3.61 ns I.03).

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