Exploration of hybrid cladding elements in chalcogenide hollow-core fibers for low-loss mid-infrared transmission

Nested multibar cladding elements in negative curvature fibers for CO laser guidance

“…The real part of the refractive index used for the cladding in our numerical models for As 2 S 3 , As 2 Se 3 , and silica glass at the centered wavelength of 5.4 μm was around 2.40, 2.79, and 1.31 respectively. More details regarding the simulation method used in this paper can be found in our previous work [18,42].…”

“…Infrared (IR) transparent soft glasses have attractive material properties and are usually preferred to design NCFs for different applications in the mid-IR spectral region [15][16][17]. Over the years, various chalcogenide glass-based NCFs have been proposed in the mid-IR spectrum due to the favorable optical properties of chalcogenides [12,16,[18][19][20][21][22][23][24]. Chalcogenide glasses such as As 2 S 3 and As 2 Se 3 have good material transparency in the mid-IR spectrum, and they are suitable for the thermal fiber drawing process, that is a robust fabrication method amenable to kilometer-long fiber drawing.…”

“…The spectral region centered at 5.4 μm is important for the CO laser, an alternative light source in the mid-IR region for material processing and spectroscopy [17]. Various NCF structures such as tubular [11], elliptical [18,19,34], lotus-shaped [35], conjoined-tube [36], double-ring [37], adjacent nested [38], nested compounded [39], double nested [40,41], and bar supported NCFs [41][42][43][44] have been reported to improve the transmission losses of hollow-core structures. Although several studies on bar-supported structures have been reported, they are mainly focused on light guidance in either the near-IR or terahertz (THz) regions.…”

Frequency selective low-loss transmission in negative curvature hollow-core fibers

“…Negative curvature hollow-core optical fibers (shortly as NCFs) which have negatively curved or hypocycloid cladding elements surrounding the hollow-core lead the way to the sub-1 dB/km measured losses in the near-infrared (near-IR) region by increasing the phase mismatch and, at the same time, decreasing the spatial overlap between the core and cladding modes [2]. Within the cladding structure of the NCFs, various types of elements were proposed, and several studies were focused on developing nested elements that have a remarkable impact towards the development of ultralow loss fibers [3][4][5][6][7]. On the other hand, specific design alterations of nested elements open the path for several optical phenomena, including polarization maintenance and spectral filtering.…”