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In this paper, we demonstrated two kinds of variable photonic devices: microlens and phase modulator. Both of them work based on the principle of dielectric-force-induced surface deformation. For each device, we depict its structure as well as the device fabrication processes. Their performances were tested and evaluated using optical microscope. Based on our investigation, such a deformable liquid...
The LCD is proposed as a new phase shifter with the advantage that the phase shifting is controlled digitally with no any mechanical moving and rotating elements. Phase shifting can be readily introduced by changing the coded image displayed on the LCD. Hence the LCD's phase modulation characteristics are analyzed theoretically and experimentally. A short overview of different calibration methods...
In this paper we investigate the evolutions of Bloch vector in a dense two-level system with near-dipole-dipole (NDD) interactions driven by ultrafast incident pulses, whose duration is far less than the relaxation times. The results show that the evolutionary relationships between dispersion (absorption) and inversion, as function of NDD parameter, are reciprocal. And the pulse width and pulse area...
we present a theoretical study on a four-level atom system with a triplet ground state and an exicited state driven by two coupling fields, a rf field and a probe field. The absorption spectrum is characterized by two EIT. It can be found that the linewidth of the two EIT change with the relative phase of the two coupling fields. The linewidth reaches the minimum when the relative phase is equal to...
An intensity-modulation direct-detection (IMDD) radio-over-fiber link with a tunable transfer function is presented. It utilizes a bias drift free intensity modulator based on a Sagnac fiber loop interferometer containing an optical phase modulator. By adjusting the polarization controller in the interferometer, the transfer function of the whole system can be tuned. The present method is simple and...
An asymmetric path ridge waveguide for an organic polymer Mach-Zehnder modulator was designed to make the initial phase difference between the two arms be π/2. The mode characteristic is analyzed and the ridge waveguide is designed with effective index method (EIM). Optical field distribution has been simulated by Beam Propagation Method (BPM). Aiming at a smaller conductor loss and better impedance...
In this paper, we present simulation results for the bit error rate (BER) performance and the fading penalty of a BPSK subcarrier intensity modulation (BPSK-SIM) free-space optical (FSO) communication link in a log-normal atmospheric turbulence model. The results obtained are based on the Monte-Carlo simulation. Multiple subcarrier modulation schemes offer increased system throughput and require no...
Conditions and gain spectra of modulation instability (MI) induced by combined effects of self-phase modulation and waveguide dispersions are investigated, taking into account the linear loss and two-photonic absorption (TPA) of silicon-on-insulator (SOI) waveguide simultaneously. Formulation for calculating the gain of MI is deduced theoretically. Impacts of various parameters to gain spectra of...
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