A photonic crystal fiber (PCF) made of fused silica glass, infiltrated with carbon tetrachloride (CCl), is proposed as a new source of supercontinuum (SC) light. Guiding properties in terms of effective refractive index, attenuation, and dispersion of the fundamental mode are studied numerically. As a result, two optimized structures are selected and verified against SC generation in detail. The dispersion characteristic of the first structure has the zero-dispersion wavelength at 1.252 μm, while the dispersion characteristic of the second structure is all-normal and equals -4.37  ps·nm·km at 1.55 μm. SC generation was demonstrated for the wavelengths 1.064 μm, 1.35 μm, and 1.55 μm. We prove the possibility of coherent, octave-spanning SC generation with 300 fs pulses with only 0.8 nJ of energy in-coupled into the core with each of the studied structures. Proposed fibers are fully compatible with all-silica fiber systems and PCFs with wide mode area, and can also be used for all-fiber SC sources. The proposed solution may lead to new low-cost all-fiber optical systems.

This study proposes a photonic crystal fiber (PCF) made of fused silica glass with the core infiltrated with 1,2-dibromoethane ( C 2 H 4 B r 2 ) as a new source of supercontinuum light pulses. Due to the modifications of the PCF’s structure geometry, a number of computer simulations investigating their optimized structures has been carried out. This aimed at achieving flat near-zero dispersion and zero dispersion wavelength matching of the pump wavelength for efficient spectral broadening. Based on the obtained results, the structural geometries of two C 2 H 4 B r 2 -core PCFs were optimized using numerical modeling for broadband supercontinuum (SC) generation. The first fiber structure with a lattice constant 1.5 µm and filling factor 0.4 has all-normal dispersion profile. The SC with a broadened spectral bandwidth from 0.64 to 1.70 µm is generated by pump pulses centered at a wavelength of 1.03 µm, 120 fs duration, and energy of 1.5 nJ. The second proposed structure—with lattice constant 1.5 µm and filling factor 0.65—has anomalous dispersion for wavelengths longer than 1.03 µm. We obtained high coherence of the SC pulses in the anomalous dispersion range over wavelengths of 0.7–2.4 µm with the same pump pulse as the first fiber and with input energy of 0.09 nJ. These fibers would be interesting candidates for all-fiber SC sources operating with low-energy pump lasers as cost-effective alternatives to glass core fibers.

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In this paper we present a study on the dispersion characteristics in the suspended-core optical fibers made of borosilicate of NC21A glass infiltrated with water. Replacement of air with water results in dramatic improvement of the dispersion characteristics in the fibers, valuable in the process of supercontinuum generation. A near-zero flat dispersion can be achieved in the anomalous or normal dispersion range for various diameters of the core.

We report a numerical study on mid-infrared (IR) supercontinuum (SC) generation in the regime of all normal dispersion using lead bismuth gallate glass photonic crystal fiber. This fiber allows the changing of dispersion from anomalous dispersion to ultra-flat normal dispersion in the wavelength range of over 930 nm by filling its cladding holes with C2Cl4. Using a 12.5 kW laser pulse at 2.8 µm as a pump source, we demonstrate that a broad and highly coherent SC generation spectrum is generated in the wavelength range of 1.2 μ m –3.4 μ m with the effects of vacuum noise. However, pulse-to-pulse relative intensity noise significantly decreases the coherence. These interesting optical properties make the proposed C2Cl4—infiltrated fiber highly promising for various applications in the mid-IR regime, particularly, spectroscopy, optical coherence tomography, and metrology.

Octave spanning all-normal dispersion supercontinuum generation (SCG) was experimentally demonstrated in a solid, suspended-core fiber (SCF) infiltrated with water. Replacement of air with water in the cladding air-holes leads to a dramatic modification of the dispersion profile of the fiber, significantly flattening the characteristic over the visible and much of the near-infrared wavelength range at normal values. In such a fiber infiltrated with water, all-normal dispersion supercontinuum was generated with the spectral coverage from 435 nm to 1330 nm using femtosecond pumping with the output peak power of 150 kW and 800 nm central wavelength. The SCF without water infiltration – air in the cladding region – had a zero-dispersion wavelength at 760 nm and enabled the generation of the anomalous dispersion dynamics-based SCG in the wavelength range from 450 nm to 1250 nm. We also numerically calculated the coherence of simulated supercontinuum pulses with one-photon-per-mode noise seeds and point out that the all-normal dispersion SCG in suspended-core fiber infiltrated with water has the potential for high temporal coherence, while the fiber without water infiltration shows gradual decoherence of generated supercontinuum pulses with increasing pump power, over similar peak power range.

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Temperature change of the water infiltrated PCF is an interesting and practical method for a dynamical fine tuning of dispersion in active dispersion shift compensating systems. In this paper we present a numerical study on the influence of the temperature of infiltrated water on the dispersion and modal characteristics of photonic crystal fiber. We study regular hexagonal lattice photonic crystal fibers with various geometrical parameters using finite element method.