A photonic crystal fiber made of fused silica glass and infiltrated with nitrobenzene (C ₆ H ₅ NO ₂ ) was proposed as a new nonlinear medium for supercontinuum generation (SG). The guiding properties of the fiber structure were studied numerically, including estimation of the effective refractive index, attenuation, and dispersion of the fundamental mode. Based on the obtained results, three optimized structures were selected and tested numerically for SG. With numerical simulations of nonlinear propagation, we demonstrated the feasibility of spectrally broad and coherent SG in the proposed structures. For the first we obtained a supercontinuum (SC) in the range of 0.8–1.8 µ m, for the second in the range of 0.8–2.1 µ m, and for the third 1.3–2.3 µ m. The pulse energy was in the range of 0.06–0.5 nJ while the pulse duration was 90 fs or 120 fs. For all structures an SC was formed in the first centimeter of the light propagation and conveniently allowed to assume short segments of the fibers. The proposed fibers are good candidates for all-fiber SC sources constituting an attractive alternative to glass-core fibers, since the nonlinearity of nitrobenzene is significantly higher than that of silica. The proposed solution may lead to new low-cost all-fiber optical systems for SG.

Hollow-core optical fibers (HCFs) have unique properties like low latency, negligible optical nonlinearity, wide low-loss spectrum, up to 2100 nm, the ability to carry high power, and potentially lower loss then solid-core single-mode fibers (SMFs). These features make them very promising for communication networks and similar applications. However, this class of fibers is still in development. Current applications are almost exclusively limited to low-latency data links for High-Speed Trading (HST); other uses are in the trial stage now. In this paper, we comprehensively review the progress in the development of HCFs including fiber design, fabrication and parameters (with comparisons to conventional single-mode fibers) and support technologies like splicing and testing. A variety of HCF applications in future telecom networks and systems is analyzed, pointing out their strengths and limitations. Additionally, we review the influence of filler gas and entry of contaminants on HCF attenuation, and propose a new fusion splicing technique, avoiding the destruction of the fiber’s photonic cladding at high temperature.

A photonic crystal fiber (PCF) made of fused silica glass, infiltrated with carbon tetrachloride (${\mathrm{CCl}}_4$), 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 $-4.37\mathrm{ps}·{\mathrm{nm}}^{-1}·{\mathrm{km}}^{-1}$ 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.

A photonic crystal fiber made of fused silica glass, infiltrated with chloroform (CHCl ₃ ), 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 for and verified against SC generation in detail. The dispersion characteristic of the first structure is all-normal and equals −7 ps · nm ⁻¹ · km ⁻¹ at 0.92 μ m, while the dispersion characteristic of the second structure has the zero-dispersion wavelength at 1 μ m, and SC generation was demonstrated for the wavelength 1.03 μ m. We prove the possibility of coherent octave-wide SC generation in the wavelength range of 600–1260 nm and soliton fission based low-coherence flat SC in the wavelength range of 600–1400 nm, with 400 fs pulses and 0.8 nJ of energy in-coupled into the core of the studied structures. Proposed fibers are good candidates for all-fiber SC sources as an alternative to glass core fibers, since nonlinearity of CHCl ₃ is higher than silica and its toxicity is negligible. The proposed solution may lead to new low-cost all-fiber optical systems.

Supercontinuum generation (SG) in fused silica photonic crystal fibers (PCFs) having a core infiltrated with liquid benzene is analyzed. Three PCF designs, with dimensions and chromatic dispersion optimized for SG using off-the-shelf femtosecond pulse lasers (1560 nm, 90 ps), are proposed. F1 fiber with lattice constant Λ = 1.5 μm and linear filling factor f = 0.45 has all-normal dispersion and offers SG in the 700- to 2000-nm band at relative power levels within 15 dB when pumped with 3 nJ pulses. F2 fiber (Λ = 1.5 μm, f = 0.6) enables SG in an anomalous dispersion regime, covering 600 to 2600 nm spectral range at relative power levels within 30 dB when pumped with low-energy pulses (1 nJ). The F3 fiber (Λ = 2.5 μm, f = 0.6) also exhibits mostly anomalous dispersion and makes possible SG in a very broad 600 to 3500 nm range at relative power levels within 30 dB when pumped with 2 nJ pulses.