An FPGA-Based Pulse Pile-up Rejection Technique for Photon Counting Imaging Detectors

A novel FPGA-based pulse pile-up rejection method for single photon imaging detectors is reported. Tile method is easy to implement in FPGAs for real-time data processing. The rejection principle and entire design are introduced in detail. The photon counting imaging detector comprises a micro-channel plate （MCP） stack, and a wedge and strip anode （WSA）. The resolution mask pattern in front of the MCP can be reconstructed after data processing in the FPGA. For high count rates, the rejection design can effectively reduce the impact of the pulse pile-up on the image. The resolution can reach up to 140μm. The pulse pile-up rejection design can also be applied to high-energy physics and particle detection.

Characterization of planar photonic crystals using surface coupling techniques at large wavelengths

We report a non-destructive characterization of planar two-dimensional （2D） photonic crystals （PhCs） made in silicon on insulator （SOI） wafers using ellipsometric or Fourier transformed infrared （FTIR） spectroscope. At large wavelengths, devices behave as homogeneous isotropic materials defined by an effective filling factor. The experimental results related to the PhC limited dimensions confirm this characterization.

Robust and low-cost interrogation technique for integrated photonic biochemical sensors based on Mach–Zehnder interferometers

We describe and experimentally demonstrate a measuring technique for Mach–Zehnder interferometer(MZI)based integrated photonic biochemical sensors. Our technique is based on the direct measurement of phase changes between the arms of the MZI, achieved by signal modulation on one of the arms of the interferometer together with pseudoheterodyne detection, and it allows us to avoid the use of costly equipment such as tunable light sources or spectrum analyzers. The obtained output signal is intrinsically independent of wavelength, power variations, and global thermal variations, making it extremely robust and adequate for use in real conditions. Using a silicon-on-insulator MZI, we demonstrate the real-time monitoring of refractive index variations and achieve a detection limit of 4.1 × 10^(-6)refractive index units(RIU).

PMD and CD Characterization of Chirped FBG Using Microwave Photonic Technique

We present and demonstrate experimentally a new method for measuring the polarization-mode-dispersion(PMD) of a Chirped Fiber Bragg Grating. The technique has also been applied to accurate chromatic dispersion evaluation by removing the influence of PMD.

Photonics 60 GBaud PDM-16QAM fiber-wireless 2×2 MIMO delivery at THz-band

The terahertz photonics technique has bright application prospects in future sixth-generation(6G)broadband communication.In this study,we have experimentally demonstrated a photonics-assisted record-breaking net bit rate of 417 Gbit/s per wavelength signals delivery in a fiber-wireless converged communication system supported by advanced digital-signalprocessing(DSP)algorithms and a polarization multiplexing-based multiple-input multiple-output(MIMO)scheme.In the experiment,up to 60 GBaud(480 Gbit/s)polarization-division-multiplexing 16-ary quadrature-amplitude-modulation(PDM16QAM)signals are transmitted over 20 km fibers and 3 m wireless 2×2 MIMO links at 318 GHz with the bit error rate(BER)under 1.56×10^(−2).It is the first demonstration to our knowledge of signals delivery exceeding 400 Gbit/s per wavelength in a photonics-assisted fiber-wireless converged 2×2 MIMO communication system.