A. C. L. Wong

The Hong Kong Polytechnic University, Hong Kong, Hong Kong

Are you A. C. L. Wong?

Claim your profile

Publications (6)6.63 Total impact

  • A.C.L. Wong · W.H. Chung · H.Y. Tam · C. Lu ·
    [Show abstract] [Hide abstract]
    ABSTRACT: We report the fabrication of extremely short linear-cavity distributed Bragg reflector fiber lasers (DBR-FLs). It has a total length of 7 mm, the shortest FL being reported. The FLs are characterized in details. We constructed a FL sensor array that has great potentials for large-scale, high sensitivity sensing applications.
    Communications and Photonics Conference and Exhibition (ACP), 2010 Asia; 01/2011
  • A. C. L. Wong · W. H. Chung · H. Y. Tam · C. Lu ·
    [Show abstract] [Hide abstract]
    ABSTRACT: A low-noise, ultra-short linear-cavity distributed feedback fiber laser (DFB-FL) with extremely narrow linewidth is presented. The FL has a total length of 17 mm, which is, to our knowledge, the shortest DFB-FL being reported. It has a measured linewidth of merely 250 Hz without active stabilization. It has a polarization beat frequency of 101 MHz, which is several times lower than that of most FLs. The relaxation oscillation frequency and relative peak are 110 kHz and −76.5 dB/Hz, respectively. The FL exhibited low-noise characteristics, with an intensity noise of −107 dB/Hz at 1 MHz. Due to low dopant concentration of the EDF and low splice loss with ordinary single-mode fibers, the net insertion loss amounts to only 0.45 dB. Such low pump power loss greatly enhances the capability of multiplexing a large number of FL sensors. Thus, these ultra-short DFB-FLs open up new opportunities for the development of compact-sized point sensor array systems for large-scale high sensitivity sensing applications.
    Laser Physics 01/2011; 21(1):163-168. DOI:10.1134/S1054660X10230143 · 1.03 Impact Factor
  • Source
    Guiyao Zhou · C.-F.J. Pun · Hwa-yaw Tam · A. C. L. Wong · C. Lu · P. K. A. Wai ·
    [Show abstract] [Hide abstract]
    ABSTRACT: We demonstrate a technique for the fabrication of single-mode perfluorinated polymer optical fiber (PPOF). The PPOF preform is composed of poly-methyl-methacrylate (PMMA)-based outer cladding and a graded-index multimode PPOF as the core. A photosensitive graded-index single-mode PPOF with a core diameter of about 6.6 ??m and cladding diameter of 400 ??m was fabricated. The fiber has a cutoff wavelength of 854 nm and exhibits single-mode characteristics at wavelengths of 1310 and 1550 nm. The transmission loss is less than 0.2 dB/m in the wavelength range of 1410-1540 nm and less than 0.5 dB/m for wavelengths up to 1610 nm, significantly less than the typical transmission loss of ~100 dB/m for PMMA fiber. Another important feature of the PPOF is its low refractive index of 1.34, close to aqueous solution of biomaterials, permitting strong optical coupling for biomedical applications.
    IEEE Photonics Technology Letters 02/2010; 22(2-22):106 - 108. DOI:10.1109/LPT.2009.2036377 · 2.11 Impact Factor
  • A. C. L. Wong · M. Giovinazzo · H. Y. Tam · C. Lu · G. D. Peng ·
    [Show abstract] [Hide abstract]
    ABSTRACT: We present using a single tilted moiré fiber Bragg grating for simultaneous measurement of refractive index and temperature using the discrete wavelet transform technique. The former is obtained from the differential shift between the Bragg and cladding modes, and the latter from the Bragg mode shift only.
  • Source
    H Y Fu · A C L Wong · P A Childs · H Y Tam · Y B Liao · C Lu · P K A Wai ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Three multiplexing schemes are presented for polarization-maintaining photonic crystal fiber based Sagnac interferometric sensors. The first technique is wavelength division multiplexing using coarse wavelength division multiplexers (CWDMs) to distinguish signals from each multiplexed sensor in different wavelength channels. The other two schemes are to multiplex sensors in series along a single fiber link and in parallel by using fiber-optic couplers. While for the CWDM scheme, the multiplexed sensing signal can be obtained by direct measurement; for the other two multiplexing techniques, the sensing signal is more complex and cannot be easily demultiplexed. Thus, some signal processing methods are required. In this regard, two mathematical transformations, namely the discrete wavelet transform and Fourier transform, have been independently and successfully implemented into these two schemes. The operating principles, experimental setup, and overall performance are discussed.
    Optics Express 10/2009; 17(21):18501-12. DOI:10.1364/OE.17.018501 · 3.49 Impact Factor
  • A. C. L. Wong · H. Y. Fu · H. Y. Tam · C. Lu ·
    [Show abstract] [Hide abstract]
    ABSTRACT: For the first time, discrete wavelet transform (DWT) is used for the demultiplexing of photonic crystal fibre Sagnac interferometric sensors. This DWT technique was demonstrated experimentally through pressure measurements with sensors multiplexed in series.