Remote state-of-polarization control in polarization-maintaining fibre

Any arbitrary state of polarization of light beam can be decomposed into a linear superposition of two orthogonal oscillations, each of which has a specific amplitude of the electric field. The dispersive nature of diffractive and refractive optical components generally affects these amplitude responses over a small wavelength range, tumbling the light polarization properties. Although recent works suggest the realization of broadband nanophotonic interfaces that can mitigate frequency dispersion, their usage for arbitrary polarization control remains elusively chromatic. Here, we present a general method to address broadband full-polarization properties of diffracted fields using an original superposition of circular polarization beams transmitted through metasurfaces. The polarization-maintaining metasurfaces are applied for complex broadband wavefront shaping, including beam deflectors and white-light holograms. Eliminating chromatic dispersion and dispersive polarization response of conventional diffractive elements lead to broadband polarization-maintaining devices of interest for applications in polarization imaging, broadband-polarimetry, augmented/virtual reality imaging, full color display, etc.

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Accurate and Rigorous Calibration of Intradyne Coherent Receiver Using Polarization-Multiplexed Signal Generated within Intradyne Coherent Transmitter

Applied Sciences ◽

10.3390/app10103467 ◽

2020 ◽

Vol 10 (10) ◽

pp. 3467

Author(s):

Qiang Wang ◽

Yang Yue

Keyword(s):

Polarization Control ◽

Calibration Signal ◽

Innovative Technique ◽

State Of Polarization ◽

Active Stabilization ◽

Constant State ◽

Novel Method ◽

Coherent Receivers ◽

Coherent Receiver ◽

Optical Transceivers

Coherent optical transceivers offer significant advantages over direct-detect optical transceivers. However, both intradyne coherent transmitters (ICT) and intradyne coherent receivers (ICR) are more complicated and require careful calibration. Traditionally, an ICR is calibrated through heterodyne beating using a single-polarized signal. Active stabilization to maintain a constant state of polarization for the calibration signal is necessary, leading to a relatively complicated setup. We demonstrate a novel method through heterodyne beating using a polarization-multiplexed signal. No polarization control is needed, resulting in a much simpler configuration. The calibration results obtained through the polarization-multiplexed signal match with the results using a single polarized signal. Moreover, this polarization-multiplexed signal can be generated within the intradyne coherent transmitter without using any external components. This innovative technique enables the calibration of a coherent receiver for deployment in the field throughout its lifetime.

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Endless state-of-polarization control for coherent optical communication systems using nematic liquid crystals

10.15760/etd.6029 ◽

2000 ◽

Author(s):

Scott Rumbaugh

Keyword(s):

Liquid Crystals ◽

Optical Communication ◽

Communication Systems ◽

Nematic Liquid Crystals ◽

Polarization Control ◽

Optical Communication Systems ◽

State Of Polarization ◽

Coherent Optical Communication

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Polarization-Noise in Integrated Optical Gyro

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.483.432 ◽

2011 ◽

Vol 483 ◽

pp. 432-436

Author(s):

Zhao Kui Meng ◽

Zhi Chao Jiao ◽

Hui Lan Liu ◽

Li Shuang Feng ◽

Ru Ya Li

Keyword(s):

Integrated Circuit ◽

Ring Resonator ◽

Light Polarization ◽

Noise Sources ◽

Third Way ◽

Integrated Optical ◽

State Of Polarization ◽

Polarization Maintaining ◽

Polarization Fluctuation

Resonator Integrated Optic Gyro (R-IOG) adopts advantages of the micro integrated optoelectronic technique, whose ring resonator is fabricated by optical integrated circuit. Polarization fluctuation induced noise is one of the dominant noise sources in resonator. State of polarization (SOP) of the input light, polarization maintaining quality of the coupler and the waveguide and the fluctuation of the temperature are main parameters which affect polarization noise of integrated optical gyro. Through simulations and experiments, three countermeasures are introduced. The first and second are for exciting one polarization mode of the waveguide. The first way is modulating the SOP of the input light utilizing polarization controller or polarizer and the second one is raising polarization maintaining quality of the waveguide through the birefringence caused by residual stress and core size. The third way is increasing the distance of two resonance dips by control the temperature at an appropriate point to fix one resonance dip at the center of the other resonance interval. The polarization noise can be suppressed through the ways mentioned above.

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Group-Birefringence-Dispersion Measurements for Polarization-Maintaining Fibers Using a Kerr Phase-Interrogator

Applied Sciences ◽

10.3390/app10249031 ◽

2020 ◽

Vol 10 (24) ◽

pp. 9031

Author(s):

Yang Lu

Keyword(s):

Group Delay ◽

Laser Wavelength ◽

Differential Group Delay ◽

Optical Signals ◽

Differential Group ◽

Principal Axes ◽

Polarization Maintaining Fiber ◽

Elliptical Core ◽

Polarization Maintaining ◽

The Impact

A method which utilizes a Kerr phase-interrogator to measure the group birefringence dispersion (GBD) of a polarization-maintaining fiber (PMF) is systematically studied in this paper. The differential group delay of two sinusoidally modulated optical signals (SMOSs) polarized along the principal axes of the PMF is measured by a Kerr phase-interrogator, which leads to the group birefringence of the PMF. As the laser wavelength of the SMOSs varies, the group birefringence as a function of the laser wavelength is obtained, and the GBD is calculated as the derivative of the group birefringence with respect to the laser wavelength. The proposed method is experimentally demonstrated by characterizations of a Panda PMF with high GBD and an elliptical core PMF with low GBD, and its performance is analyzed. The proposed method eliminates the impact of the laser coherent length and allows for characterizing the GBD of PMFs that are tens of kilometers long.

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A Highly Birefringent Photonic Crystal Fiber for Terahertz Spectroscopic Chemical Sensing

Sensors ◽

10.3390/s21051799 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1799

Author(s):

Tianyu Yang ◽

Liang Zhang ◽

Yunjie Shi ◽

Shidi Liu ◽

Yuming Dong

Keyword(s):

Photonic Crystal ◽

Photonic Crystal Fiber ◽

Chemical Sensing ◽

Numerical Aperture ◽

Wide Band ◽

Relative Sensitivity ◽

Chemical Sensitivity ◽

High Birefringence ◽

Crystal Fiber ◽

Polarization Maintaining

A photonic crystal fiber (PCF) with high relative sensitivity was designed and investigated for the detection of chemical analytes in the terahertz (THz) regime. To ease the complexity, an extremely simple cladding employing four struts is adopted, which forms a rectangular shaped core area for filling with analytes. Results of enormous simulations indicate that a minimum 87.8% relative chemical sensitivity with low confinement and effective material absorption losses can be obtained for any kind of analyte, e.g., HCN (1.26), water (1.33), ethanol (1.35), KCN (1.41), or cocaine (1.50), whose refractive index falls in the range of 1.2 to 1.5. Besides, the PCF can also achieve high birefringence (∼0.01), low and flat dispersion, a large effective modal area, and a large numerical aperture within the investigated frequency range from 0.5 to 1.5 THz. We believe that the proposed PCF can be applied to chemical sensing of liquid and THz systems requiring wide-band polarization-maintaining transmission and low attenuation.

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