VTechWorks staff will be away for the Thanksgiving holiday beginning at noon on Wednesday, November 27, through Friday, November 29. We will resume normal operations on Monday, December 2. Thank you for your patience.

Browsing by Author "Shen, F. B."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Fast-Fourier-Transform Based Numerical Integration Method For The Rayleigh-Sommerfeld Diffraction Formula
    Shen, F. B.; Wang, Anbo (Optical Society of America, 2006-08-01)
    The numerical calculation of the Rayleigh-Sommerfeld diffraction integral is investigated. The implementation of a fast-Fourier-transform (FFT) based direct integration (FFT-DI) method is presented, and Simpson's rule is used to improve the calculation accuracy. The sampling interval, the size of the computation window, and their influence on numerical accuracy and on computational complexity are discussed for the FFT-DI and the FFT-based angular spectrum (FFT-AS) methods. The performance of the FFT-DI method is verified by numerical simulation and compared with that of the FFT-AS method. (c) 2006 Optical Society of America.
  • Thumbnail Image
    Frequency-Estimation-Based Signal-Processing Algorithm For White-Light Optical Fiber Fabry-Perot Interferometers
    Shen, F. B.; Wang, Anbo (Optical Society of America, 2005)
    A novel signal-processing algorithm based on frequency estimation of the spectrogram of single-mode optical fiber Fabry-Perot interferometric sensors under white-light illumination is described. The frequency-estimation approach is based on linear regression of the instantaneous phase of an analytical signal, which can be obtained by preprocessing the original spectrogram with a bandpass filter. This method can be used for a relatively large cavity length without the need for spectrogram normalization to the spectrum of the light source and can be extended directly to a multiplexed sensor system. Experimental results show that the method can yield both absolute measurement with high resolution and a large dynamic range. Performance analysis shows that the method is tolerant of background noise and variations of the source spectrum. (c) 2005 Optical Society of America.
  • Thumbnail Image
    Micro-Air-Gap Based Intrinsic Fabry-Perot Interferometric Fiber-Optic Sensor
    Chen, X. P.; Shen, F. B.; Wang, Z. A.; Huang, Z. Y.; Wang, Anbo (Optical Society of America, 2006-05-01)
    A simple intrinsic Fabry-Perot interferometric (IFPI) sensor is developed. The sensor is fabricated by two micro air gaps as reflective mirrors in a fiber to form a Fabry-Perot cavity. Theoretical and experimental studies of the sensor are described. Experimental results show that high resolution and high sensitivity can be achieved. Two structures of micro-air-gap-based IFPI sensors offer more applications than other IFPI sensors. (c) 2006 Optical Society of America.