Search

In this manuscript, we experimentally demonstrate a parity-time-symmetric optoelectronic oscillator (OEO) with polarization multiplexed channels. We obtained a microwave single-mode oscillation at 9.5 GHz with phase noise values of −116.2 and −122.3 dBc Hz−1 at 10 kHz offset frequencies, and side mode suppression values below −68 and −75 dBc Hz−1, by utilizing a 1 km long and 5 km long single mode fiber delay lines, respectively. Our experimental results suggest that parity-time-symmetric OEOs with polarization multiplexed channels are simple and cost-efficient alternatives to their more complex counterparts.

Date of Conference: 19–23 July 2021 Conference name: OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES) We experimentally investigate the effect of the probe pulse shape on the performance of φ-OTDR based distributed vibration sensors by comparing the SNR values for rectangular, Gaussian and triangular pulses.

Conference name: 2020 Conference on Lasers and Electro-Optics Pacific Rim, CLEO-PR 2020 - Proceedings Date of Conference: 3–5 August 2020 We theoretically model and experimentally demonstrate the photon statistics of Rayleigh backscattered signal in a ϕ-OTDR based distributed fiber optical sensor in the presence of amplified spontaneous emission noise caused by optical pre-amplifier.

This work was partially supported by The Scientific and Technological Research Council of Turkey (TUBITAK) under Grant 3190696 and ASELSAN A.S. In this work, we present the experimental results of a direct detection phi-OTDR based distributed acoustic sensor system. The system uses two cascaded acousto-optic modulators in order to generate optical pulses with very high extinction ratio and dual photodetector scheme for high dynamic range. The proposed schemes are investigated in detail and their performance enhancement is experimentally verified. Four piezoelectric based fiber stretchers are placed on a similar to 104 km single-mode test fiber at the distances of 1 km, 10 km, 87 km and 102.7 km and used for perturbation tests. The stretchers generated vibration signals which are analyzed to quantify the system performance. The signal-to-noise ratio (SNR) of vibration signals at the monitored distances is measured over the 12-hour recorded data within 34-second time windows considering the multi-point random interference of scattered light and fading phenomena. Using the 12-hour data, SNR histograms at four different locations are generated and mean SNR values are obtained. The signals received from 102.7 km has a maximum SNR of 24.7 dB and a mean SNR of 7.3 dB with a spatial resolution of 15 m. To the best of our knowledge, this is the highest-range reported direct detection phi-OTDR based distributed acoustic sensor system. Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) 3190696 ASELSAN A.S.

Date of Conference: 5-10 May 2019 Conference name: Conference on Lasers and Electro-Optics This work demonstrates an ultra-long range direct detection fiber optic distributed acoustic sensor which can detect vibrations at a distance of 94.8 km with 10 m resolution along the sensing fiber.

We are pleased to acknowledge Dr. D. Noordegraaf of NKT Photonics for the loan of the photonic lantern device used in the experiments. The experimental work of this manuscript is supported by the internal funding of Applied Communication Sciences and the numerical calculations are supported by The Scientific and Technological Research Council Of Turkey (TUBITAK) Project no 114E402. In this work, a photonic-lantern-based coherent LIDAR system is experimentally demonstrated and the voltage signal-to-noise ratio improvement is analyzed. A voltage signal-to-noise ratio (SNRV) improvement of 2.8 is demonstrated experimentally for photonic-lantern-based coherent receivers relative to single-mode coherent receivers. The voltage signal-to-noise ratio improvement is obtained when other parameters are kept constant. We have also analyzed the effect of random optical power distribution among the single-mode fibers. We found that the distribution does not significantly impact the SNRV improvement. The mean value of voltage signal-to-noise ratio improvement is found to be similar to 2.4. (C) 2015 Optical Society of America Applied Communication Sciences Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) 114E402