A fiber optic phase modulator with an optical frequency shift of up to 20 GHz (original) (raw)
Related papers
Numerical modeling of a fiber-optic phase modulator using piezoelectric polymer coating
IEEE Photonics Technology Letters, 2000
A new approach in analysing an all-fiber phase modulator using a commercially available finite-element software package is presented. A single-mode fiber coated with a radially poled piezoelectric unoriented vinylidene fluoride (73 mol%)/trifluoroethylene (27 mol%) copolymer was successfully modeled using a two-dimensional axi-symmetric approach. The response of the phase modulator was determined over a wide frequency range, from 10 Hz to 50 MHz. Results showed a phase shift of 0.155 rad/V/m in the low-frequency (axially unconstrained) region, and 0.045 rad/V/m in the high-frequency (axially constrained) region. An excellent agreement exists between the simulation results and experimental measurements.
APL Photonics
An opto-electronic radio-frequency oscillator that is based on forward scattering by the guided acoustic modes of a standard single-mode optical fiber is proposed and demonstrated. An optical pump wave is used to stimulate narrowband, resonant guided acoustic modes, which introduce phase modulation to a co-propagating optical probe wave. The phase modulation is converted to an intensity signal at the output of a Sagnac interferometer loop. The intensity waveform is detected, amplified, and driven back to modulate the optical pump. Oscillations are achieved at a frequency of 319 MHz, which matches the resonance of the acoustic mode that provides the largest phase modulation of the probe wave. Oscillations at the frequencies of competing acoustic modes are suppressed by at least 40 dB. The linewidth of the acoustic resonance is sufficiently narrow to provide oscillations at a single longitudinal mode of the hybrid cavity. Competing longitudinal modes are suppressed by at least 38 dB as well. Unlike other opto-electronic oscillators, no radio-frequency filtering is required within the hybrid cavity. The frequency of oscillations is entirely determined by the fiber opto-mechanics.
Modeling and Design of a Micromechanical Phase-Shifting Gate Optical Modulator
This paper reports the modeling and design of a micromechanical optical modulator with a phase-shifting gate that utilizes optical interference effects to modulate light. The gate is opened or closed by microactuators integrated on the same chip, modulating light beams between stationary optical fibers. Modeling results show optimized designs can have high modulation efficiency of 99.5%, and contrast ratio of 23 dB. Alignment between fibers is guaranteed by guiding grooves available in standard MEMS batch fabrication techniques, which also permits coupling distance between fibers to be minimized. The insertion loss for a typical design can be less than-1.9 dB. The beam profile shows negligible distortion for 40µm or lower coupling distances.
Experimental study of a phase modulator using an active interferometric device
Proceedings of the Mediterranean Electrotechnical Conference - MELECON, 2010
A novel architecture for an optical phase modulator is presented and experimentally demonstrated. This approach relies on a commercially available integrated Mach-Zehnder interferometer structure with Semiconductor Optical Amplifiers (MZI-SOA) and it is based in cross-phase modulation effect (XPM). The feasibility of the proposed optical phase modulator is experimentally investigated using different scenarios of input power and bit rates.
Optical microfiber phase modulator directly driven with low-power light
Chinese Optics Letters, 2014
An optical microfiber phase modulator (OMPM) directly driven with low-power light is presented. Phase modulation response of OMPM is theoretically analyzed. A 10-mm optical microfiber (OM), tapered from conventional single-mode fiber, is inserted in one arm of a Michelson fiber interferometer. To drive the OMPM, 980-nm wavelength light with sinusoidal intensity modulation is injected into the interferometer. The OMPM response properties are measured and p-phase modulation amplitude can be obtained with only 7.5-mW average power light at 1-kHz modulation frequency. The OMPMs shown in this study have advantages of simple structure, potential compact size, and low-power-driven light.
Direct modulation of an opto-electronic oscillator: Towards radio over fiber
The 2010 International Conference on Advanced Technologies for Communications, 2010
This paper presents a new technique for direct frequency modulation of an optoelectronic oscillator (OEO) that can be applied to radio over fiber technology. The method is based on an optically controlled phase shifter. The control element is a semiconductor optical amplifier (SOA) which is inserted in the OEO loop. By this way a voltage controlled OEO (VC-OEO) is realized. It is then demonstrated that a modulation index of 5.45 can be obtained by applying to the SOA a driving sine signal with 360 mV amplitude and 1 kHz frequency.
Optical phase modulators using deformable waveguides actuated by micro-electro-mechanical systems
Optics Letters, 2011
An optical phase modulator is presented by using micro-electro-mechanical systems to actuate deformable silicon waveguides. Via mechanically stretching the waveguide length, the optical path is extended, resulting in a phase shift. The experimental results show that a phase shift of near 0:4π is achieved at 200 V for both TE-and TM-polarized waves by cascading six phase modulation units, agreeing well with the theoretical prediction. The power consumption is estimated to be smaller than 0:2 mW at 200 V, mainly resulting from the leakage current.
Non-resonant recirculating light phase modulator
APL Photonics
High efficiency and a compact footprint are desired properties for electro-optic modulators. In this paper, we propose, theoretically investigate, and experimentally demonstrate a recirculating phase modulator, which increases the modulation efficiency by modulating the optical field several times in a non-resonant waveguide structure. The “recycling” of light is achieved by looping the optical path that exits the phase modulator back and coupling it to a higher order waveguide mode, which then repeats its passage through the phase modulator. By looping the light back twice, we were able to demonstrate a recirculating phase modulator that requires nine times lower power to generate the same modulation index of a single pass phase modulator. This approach to modulation efficiency enhancement is promising for the design of advanced tunable electro-optical frequency comb generators and other electro-optical devices with defined operational frequency bandwidths.