All-fiber systems for third harmonic generation are of great interest because they can be used for the inverse process, namely, the generation of entangled photon triplets. Usually, chromatic dispersion prevents phase matching between the incident and generated radiation when they are both guided in an LP01-like mode. Here, we present a hybrid photonic crystal fiber that has been designed for phase matched third harmonic generation from 1596 to 532 nm in single-lobed modes. The third harmonic radiation is guided by an all-solid bandgap microstructure, while the pump frequency is confined by conventional total internal reflection. The fiber is also suitable for the generation of photon triplet states.
Current sensing using circularly birefringent twisted solid-core photonic crystal fiber
R. Beravat,
G. K. L. Wong,
X. M. Xi,
M. H. Frosz,
P. St. J. Russell
Continuously twisted solid-core photonic crystal fiber (PCF) exhibits pure circular birefringence (optical activity), making it ideal for current sensors based on the Faraday effect. By numerical analysis, we identify the PCF geometry for which the circular birefringence (which scales linearly with twist rate) is a maximum. For silica-air PCF, this occurs at a shape parameter (diameter-to-spacing ratio of the hollow channels) of 0.37 and a scale parameter (spacing-to-wavelength) of 1.51. This result is confirmed experimentally by testing a range of different structures. To demonstrate the effectiveness of twisted PCF as a current sensor, a length of fiber is placed on the axis of a 7.6 cm long solenoid, and the Faraday rotation is measured at different values of dc current. The system is then used to chart the wavelength dependence of the Verdet constant. (C) 2016 Optical Society of America
High-resolution wavefront shaping with a photonic crystal fiber for
multimode fiber imaging
Lyubov V. Amitonova,
Adrien Descloux,
Joerg Petschulat,
Michael H. Frosz,
Goran Ahmed,
Fehim Babic,
Xin Jiang,
Allard P. Mosk,
Philip St. J. Russell, et al.
We demonstrate that a high-numerical-aperture photonic crystal fiber allows lensless focusing at an unparalleled resolution by complex wavefront shaping. This paves the way toward high-resolution imaging exceeding the capabilities of imaging with multi-core single-mode optical fibers. We analyze the beam waist and power in the focal spot on the fiber output using different types of fibers and different wavefront shaping approaches. We show that the complex wavefront shaping technique, together with a properly designed multimode photonic crystal fiber, enables us to create a tightly focused spot on the desired position on the fiber output facet with a subwavelength beam waist. (C) 2016 Optical Society of America
All-optical bit storage in a fibre laser by optomechanically bound states of solitons
Soliton fibre lasers mode-locked at a high harmonic of their round-trip frequency have many potential applications, from telecommunications to data storage(1). Control of multiple pulses in passively mode-locked fibre lasers has, however, proved very difficult to achieve. This has recently changed with the advent of fibre lasers mode-locked by intense optomechanical interactions in a short length of photonic crystal fibre(2,3). Optomechanical coupling between cavity modes gives rise to highly stable, optomechanically bound, laser soliton states. The repetition rate of these states corresponds to the mechanical resonant frequency in the photonic crystal fibre core(4), which can be a few gigahertz. Here we show that this system can be successfully used for programmable generation and storage of gigahertz-rate soliton sequences over many hours.
Broadband robustly single-mode hollow-core PCF by resonant filtering of
higher-order modes
Patrick Uebel,
Mehmet C. Guenendi,
Michael H. Frosz,
Goran Ahmed,
Nitin N. Edavalath,
Jean-Michel Menard,
Philip St. J. Russell
We report a hollow-core photonic crystal fiber that is engineered so as to strongly suppress higher-order modes, i.e., to provide robust LP01 single-mode guidance in all the wavelength ranges where the fiber guides with low loss. Encircling the core is a single ring of nontouching glass elements whose modes are tailored to ensure resonant phase-matched coupling to higher-order core modes. We show that the resulting modal filtering effect depends on only one dimensionless shape parameter, akin to the well-known d/Lambda parameter for endlessly single-mode solid-core PCF. Fabricated fibers show higher-order mode losses some similar to 100 higher than for the LP01 mode, with LP01 losses <0.2 dB/m in the near-infrared and a spectral flatness similar to 1 dB over a >110 THz bandwidth. (C) 2016 Optical Society of America
Solid-core and hollow-core photonic crystal fiber for generation of bright ultraviolet light (Conference Presentation)
Nicolas Y. Joly,
Xin Jiang,
John C. Travers,
Alexey Ermolov,
Philip St. J. Russell
UV and Higher Energy Photonics: From Materials to Applications
UNSP 992608
(2016)
| Journal
Supercontinuum generation in ZBLAN glass photonic crystal fiber with six nanobore cores
Xin Jiang,
Nicolas Y. Joly,
Martin A. Finger,
Fehim Babic,
Meng Pang,
Rafal Sopalla,
Michael H. Frosz,
Samuel Poulain,
Marcel Poulain, et al.
