The Fabry-Perot Electrooptic Modulator

Abstract

The Fabry‐Perot modulator, consisting of Fabry‐Perot etalon plates separated by an electrooptic material such as KDP, is analyzed in detail. Time‐dependent perturbation theory is used to describe the coupling of the axial modes by spatial and time varying perturbations in the dielectric constant. The perturbations are produced by the applied microwave modulating field. It is shown that the correct choice of the spatial variation of the microwave modulating field is essential to achieve efficient modulation and the choice is equivalent to matching the phase velocities of the microwaves and the light. Power requirements, heating, and bandwidth are discussed and a comparison is made to the traveling‐wave modulator described by Kaminow. Calculations indicate that bandwidths of several hundred megacycles, centered at any microwave frequency, can be obtained with the expenditure of several watts of modulating power.

Compact electro-absorption modulator integrated with vertical-cavity surface-emitting laser for highly efficient millimeter-wave modulation

“…5. 31 The resonant frequency and the enhancement in the modulation amplitude are almost in agreement with the experiment. It is noted that the second and third peaks at 68 GHz and 100 GHz appear with an amplitude enhancement of over 50 dB.…”

“…We calculated the small-signal modulation response of the modulator integrated VCSEL using a Fabry-Perot etalon model 31 with an electro-absorption. Figure 7 shows the calculated small signal response with a modulator length of 25 lm and a group index of 150.…”

Low-Cost, High-Performance Analog Optical Links

“…PSI chose to reinvestigate the FP modulator because there have been many advances in linearization, wavelength stabilization, and fabrication of high-reflectivity mirrors since the FP was first proposed for analog links 14 . Vertical FP modulators with bandwidths as high as 37 GHz 15 have been realized in semiconductors; however the optical attenuation has limited the effective Vπ to ~3 V. The key to implementing this approach is micron-thin LiNbO 3 or other electro-optic material.…”

“…The transfer function of a FP modulator has been shown in more than one instance 16,17 to be: where I and λ are the optical intensity and wavelength, respectively, R 1 and R 2 are the input and output mirror reflectivities, respectively, α is the optical attenuation per unit length in the FP cavity, and n and L are the index of refraction and length of the cavity, respectively. What we wish to illustrate can be seen more clearly if we simplify Equation 1 by defining R 1 =R 2 =R and assuming that attenuation in the cavity is negligible (i.e., α~0).…”

Electro-optic modulation using single-crystal film of an organic molecular salt in a Fabry-Perot cavity

“…Therefore the modulation depth for both phase and amplitude modulation can be greatly enhanced. [5][6][7][8] Fabry-Perot cavities involving an organic single-crystal film and polymeric electro-optic material have been demonstrated. 5,6 In this letter, a multiple pass electro-optic modulator involving a DAST crystal-film inside a Fabry-Perot cavity is discussed.…”