We report a photonic crystal fiber (PCF) coupler having an ultrawide spectral bandwidth keeping single mode operation. The use of the PCF coupler in a fiber-based optical coherence tomography (OCT) system enables us to handle the wide spectral bands of various light sources, including superluminescent diodes (SLDs) at 1300 nm and 820 nm, Ti:sapphire lasers, and white-light sources. The multiband imaging performances of the PCF-based OCT system are demonstrated by obtaining dental images at 1300 nm and 820 nm with the same setup. In addition, we show that the PCF coupler could cover the spectrum over a one octave span and guide both the fundamental wave (1030 nm) and the second harmonic wave (515 nm) simultaneously.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3368709 | PMC |
http://dx.doi.org/10.1364/AO.49.001986 | DOI Listing |
An in-fiber Mach-Zehnder interferometer (MZI) is proposed and experimentally demonstrated for relative humidity (RH) and temperature measurements. The MZI is formed by a grapefruit-shaped photonic crystal fiber (G-PCF) cascaded with a short section of multimode fiber that serves as a mode coupler. To enhance sensitivity to humidity, femtosecond laser micromachining was performed to remove a portion of cladding of the G-PCF to expose its core to the ambient medium.
View Article and Find Full Text PDFA broadband TE(01) mode fiber coupler based on dual-core photonic crystal fiber (PCF) is proposed by introducing gold nanowires and fluorine-doped (F-doped) layers in the core areas. With an appropriate choice of the parameters of the F-doped layers and air hole space, the wavelength bandwidth can be increased to beyond 500 nm with the coupler length below 0.1 m for the 3 dB fiber coupler.
View Article and Find Full Text PDFNumerical analysis of single and multiple gold nanowires embedded in triple cores arranged in collinear and noncollinear configurations in photonic crystal fibers (PCFs) is reported. A full-vectorial finite element method is used to achieve coupling characteristics of plasmonic PCF couplers for both x and y polarizations. It is demonstrated numerically that the PCF plasmonic couplers exhibit polarization-independent tunable broadband filter characteristics that can be tuned according to the diameter of the embedded gold rod(s).
View Article and Find Full Text PDFOpt Express
March 2013
Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education, and Shaanxi Key Laboratory of Optical Information Technology, School of Science, Northwestern Polytechnical University, Xi'an 710072, China.
We numerically investigate the polarization-dependent coupling in dual-core photonic crystal fibers (PCFs) selectively filled with gold wires in air holes. It is shown that the even and odd supermodes exhibit significantly different dispersion and loss when one gold wire is filled in between two cores. The enhanced birefringence and polarization-dependent attenuation of the supermodes support the separation of two orthogonally polarized components as well as polarization-dependent transmissions with a high degree of polarization in gold-filled dual core PCFs.
View Article and Find Full Text PDFOpt Lett
November 2012
Department of Electrical Engineering, The Hong Kong Polytechnic University, Hong Kong, China.
A photonic crystal fiber (PCF) with embedded coupler is demonstrated for strain measurement. The embedded coupler is constructed by the selective filling of one of the air holes in the PCF. Light propagated in the fiber core can be efficiently coupled to the liquid-filled rod waveguide under phase-matching conditions, resulting in sharp decreasing of resonant wavelength intensity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!