The first pulsar discovered by FAST

To assist with the commissioning [1] of the Five-hundredmeter Aperture Spherical radio Telescope (FAST), we performed a pulsar search, with the primary goal of developing and testing the pulsar data acquisition and processing pipelines. We tested and used three pipelines, two (Pl and P2 hereafter) searched for the periodic signature of pulsars whereas the other one was used to search for bright single pulses (P3 hereafter).

Real-time wavelength routing based on Bragg reflection with integrated forward Raman for long-reach networks

We experimentally demonstrate the all-optical efficient technique for dynamic full-duplex wavelength routing and reach extension through adoption of passive fibre Bragg grating(FBG),energy efficient vertical cavity surface emitting lasers(VCSELs)and high gain forward Raman pump.In this study,two VCSEL channels at 1549.62 nm and 1550.01 nm are directly modulated with a 8.5 Gbit/s data signal each,and transmitted over 25.5 km fibre to a passive single mode FBG-based wavelength routing node.The precise wavelength selectivity of the FBG is exploited to achieve all-optical real-time wavelength routing of the 1549.62 nm VCSEL channel with a maximum insertion loss of 22.1 dB.The 1550.01 nm channel is transmitted through the FBG with a maximum penalty of 1.03 dB.By utilizing the 7.2 dB flat gain of a forward Raman pump,the routed 1549.62 nm VCSEL channel is transmitted over 76.7 km fibre with a maximum penalty of 3.84 dB at bit error rate(BER)of 5-5.Our technique is all-optical,power efficient as it employs passive FBG and circulators and has low cross talk allied to precise wavelength selectivity of the technique.

Inherent EDFA cross-gain saturation functionality for 17 Gbit/s PAM-3 all-optical wavelength reuse PON

In this work, inherent data-erasing functionality of a saturated erbium doped fibre amplifier(EDFA) is exploited to achieve an all-optical wavelength reuse with pulse amplitude modulation(PAM) format. A 10 GHz bandwidth distributed feedback laser(DFB) is directly modulated with 17 Gbit/s PAM-3 data signal and transmitted downstream over a 26.58 km fibre optical line terminal(OLT) incurring a maximum penalty of 1.81 d B. A saturated EDFA deployed at the optical network unit(ONU) terminal is utilized to optically suppress the extinction ratio of residual 17 Gbit/s PAM-3 downstream data significantly from 7.1 d B to 830 md B. This facilitates direct reuse of the downstream carrier without the need for an additional electrical data eraser. With the all optical data erasing capability of EDFA over-10 d Bm input power, the carrier re-used upstream transmission successfully delivers 17 Gbit/s PAM-3 data with a maximum transmission penalty of 0.99 d B. PAM-3 modulation format maximizes network efficiency by doubling the transmitted bits per symbol. Our technique is all-optical, it can support ultrafast systems with higher modulation formats and is power efficient.