Optical Properties of Low Loss (70dB/km) Hypocycloid-Core Kagome Hollow Core Photonic Crystal Fiber for Rb and Cs Based Optical Applications

Optimized inhibited-coupling Kagome fibers at Yb-Nd:Yag (85 dB/km) and Ti:Sa (30 dB/km) ranges

“…A minimum and record value is obtained at 750 nm with 30 dB/km on this fundamental transmission band [see Fig. 4(a)] for a bending radius of 35 cm, which is more than twofold lower than our previous Ti:Sa spectral range optimized HC-PCF [16]. Moreover, the current fiber exhibits losses below 150 dB/km over a large spectral range spanning from 690 to 1300 nm.…”

“…Since then, much progress has been made in both understanding the entailed guidance mechanism [2] and in its transmission performance. The latter has been continuously improved since the introduction of hypocycloid core contour (i.e., negative curvature core contour) in 2010, which led, within a short period of time, to several and successive record loss figures in the visible/ near-infrared [3,5,11,16,17]. The most recent one reported presents a loss figure of 7.7 dB/km at 750 nm using tubular amorphous lattice HC-PCF [7].…”

“…The introduction of hypocycloid core contour was a direct consequence of the IC mechanism where the fiber-core guidance is based on strongly reducing the optical overlap between the guided core mode and the continuum cladding modes. This in turn explains the loss reduction from a decibel per meter (dB/m) level in the first IC guiding HC-PCF, which took the form of a Kagome lattice cladding surrounding a hollow core with a circular [1] or a hexagonal core contour [2], to a tens of dB/km level in hypocycloid core-contour HC-PCF [3,5,11,16,17]. The impact of the corecontour geometry on the fiber confinement loss (CL) was detailed in [5], where it was shown that the larger the negative curvature of the core-contour cups, the lower the CL and fraction of the power overlap one can reach.…”

Lamb-Dicke spectroscopy of atoms in a hollow-core photonic crystal fibre

“…5c). This is the smallest silica strut thickness so far reported for a hypocycloid core HC-PCF33. This allows the fibre to guide light with low loss for wavelengths as short as 400 nm (see Fig.…”

Ultra low-loss hypocycloid-core Kagome hollow-core photonic crystal fiber for green spectral-range applications

“…The seminal introduction in 2010, of a hypocycloid corecontour (i.e., negative curvature) inhibited coupling (IC) guiding hollow-core photonic crystal fiber (HC-PCF) [1,2], has led to a dramatic transmission loss reduction, as illustrated in the record loss figure of 70 dB∕km around 780 nm [3], and 17 dB∕km in the vicinity of the 1 μm wavelength range [4,5]. These results stem from the IC guidance mechanism model [6], which predicts that negative curvature core-contour enhances the reduction of the transverse mismatch between the fundamental core mode and the cladding continuum modes, via a strong drop in the overlap integral between the two types of modes [4,5].…”