14 research outputs found
Plug&Play Fiber‐Coupled 73 kHz Single‐Photon Source Operating in the Telecom O‐Band
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.BMBF, 05M20ZBM, Forschungscampus MODAL - Mathematical Optimization and Data Analysis Laboratories - zweite Förderphase (Stabilisierung)TU Berlin, Open-Access-Mittel – 202
Spectral-domain measurement of strain sensitivity of a two-mode birefringent side-hole fiber
The strain sensitivity of a two-mode birefringent side-hole fiber is measured
in the spectral domain. In a simple experimental setup comprising a broadband source, a
polarizer, a two-mode birefringent side-hole fiber under varied elongations, an analyzer and
a compact spectrometer, the spectral interferograms are resolved. These are characterized by
the equalization wavelength at which spectral interference fringes have the highest visibility
(the largest period) due to the zero group optical path difference between the fundamental,
the LP01 mode and the higher-order, the LP11 mode. The spectral interferograms with the
equalization wavelength are processed to retrieve the phase as a function of the wavelength.
From the retrieved phase functions corresponding to different elongations of a two-mode
birefringent side-hole fiber under test, the spectral strain sensitivity is obtained. Using
this approach, the intermodal spectral strain sensitivity was measured for both x and
y polarizations. Moreover, the spectral polarimetric sensitivity to strain was measured
for the fundamental mode when a birefringent delay line was used in tandem with the
fiber. Its spectral dependence was also compared with that obtained from a shift of the
spectral interferograms not including the equalization wavelength, and good agreement was
confirmed.Web of Science129120811207