We experimentally characterized a holey fiber, in which birefringence is induced by two large holes adjacent to the fiber core. Employing a lateral force method, we measured the spectral dependence ...of the phase modal birefringence for E11 and E21 spatial modes. The group modal birefringence was also measured for both spatial modes using scanning wavelength method. Finally, we determined the fiber polarimetric sensitivity to hydrostatic pressure and to strain for E11 and E21 modes in a wide spectral range. Using special procedures, we also identified the sign of all measured parameters.
A user‐friendly, fiber‐coupled, single‐photon source operating at telecom wavelengths is a key component of photonic quantum networks providing long‐haul, ultra‐secure data exchange. To take full ...advantage of quantum‐mechanical data protection and to maximize the transmission rate and distance, a true quantum source providing single photons on demand is highly desirable. This great challenge is tackled by developing a ready‐to‐use semiconductor quantum‐dot‐based device that launches single photons at a wavelength of 1.3 µm directly into a single‐mode optical fiber. In the proposed approach, the quantum dot is deterministically integrated into a nanophotonic structure to ensure efficient on‐chip coupling into a fiber. The whole arrangement is integrated into a 19ʺ compatible housing to enable stand‐alone operation by cooling via a compact Stirling cryocooler. The realized source delivers single photons with a multiphoton events probability as low as 0.15 and a single‐photon emission rate of up to 73 kHz into a standard telecom single‐mode fiber.
A user‐friendly, compact, and portable triggered single‐photon source operating in the telecom O‐band is demonstrated. The device provides single photons with g(2)(0) = 0.15 and a flux of up to 73 kHz at a standard physical‐contact single‐mode fiber connector output. A fully deterministic fabrication technology makes it the first application‐ready quantum‐dot‐based source to enable ultra‐secure data exchange in future fiber‐based quantum communication networks.
In this paper we present an analytical formula for bending loss oscillations in photonic crystal fibers (PCFs). We follow the approach originally adopted for conventional double-clad fibers and show ...that it can be applied to PCFs by substituting the structural parameters of the conventional fiber by their PCF counterparts. We then examine the spectral dependence of the critical bending radius and the position of the first order loss peak as a function of structural parameters of the PCF cladding such as the fill factor and the number of hole rings. Finally, we evaluate the precision of the analytical model by comparing the results to finite element calculations for a selection of PCF geometries.
We experimentally characterized a birefringent side-hole microstructured fiber in the visible wavelength region. The spectral dependence of the group and phase modal birefringence was measured using ...the methods of spectral interferometry. The phase modal birefringence of the investigated fiber increases with wavelength, but its positive sign is opposite to the sign of the group modal birefringence. We also measured the sensing characteristics of the fiber using a method of tandem spectral interferometry. Spectral interferograms corresponding to different values of a physical parameter were processed to retrieve the spectral phase functions and to determine the spectral dependence of polarimetric sensitivity to strain, temperature and hydrostatic pressure. A negative sign of the polarimetric sensitivity was deduced from the simulation results utilizing the known modal birefringence dispersion of the fiber. Our experimental results show that the investigated fiber has a very high polarimetric sensitivity to hydrostatic pressure, reaching -200 rad x MPa(-1) x m(-1) at 750 nm.
We present the complete (analytical, numerical and experimental) analysis of intermodal-vectorial four-wave mixings proccesses in birefringent fibers. We analyze phase-matching condition and overlap ...coeffi-cients to indicate possible processes. Then, we demonstrate multiple four-wave mixing processes in LP
01
and LP
11
modes numerically and experimentally. Finally, we extend theoretical analysis to account higher-order modes: LP
02
and LP
21
.
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