Abstract: A hollow-core antiresonant fiber (HC-ARF) with nested supporting rings (NSRs) has a fiber structure that includes from the inside out a fiber core, a first silica antiresonant ring (SARR), a first air antiresonant ring (AARR), a second SARR, a second AARR and an external silica wall. The fiber structure further includes a first NSR within the first AARR and a second NSR within the second AARR. The HC-ARF with NSRs has advantages and benefits of low confined loss (CL), large bandwidth, simple structure and very good bending characteristics. Therefore, the application fields of HC-ARF are greatly expanded.

Abstract: A hollow-core antiresonant fiber (HC-ARF) with nested supporting rings (NSRs) has a fiber structure that includes from the inside out a fiber core, a first silica antiresonant ring (SARR), a first air antiresonant ring (AARR), a second SARR, a second AARR and an external silica wall. The fiber structure further includes a first NSR within the first AARR and a second NSR within the second AARR. The HC-ARF with NSRs has advantages and benefits of low confined loss (CL), large bandwidth, simple structure and very good bending characteristics. Therefore, the application fields of HC-ARF are greatly expanded.

Abstract: The nondestructive determination of core size of a hollow-core photonic bandgap fiber (HC-PBF) using Fabry-Perot (FP) interference is performed with an apparatus including a tunable laser source (TLS), a 1×2 single-mode (SM) coupler, an SM collimator, a six-axis translation stage, an optical detector, and an oscilloscope. The light from the TLS passes through the 1×2 SM coupler and the SM collimator to perpendicularly enter two parallel air-SiO2 interfaces of the core of the fiber and is reflected, while the TLS is tuned from one wavelength to another. Then the reflected spectrum is guided to the optical detector, where its interference intensity is converted into voltage intensity to be displayed at the oscillator and fitted with a least-squares method to obtain the distance between the two air-SiO2 interfaces. The core size of the fiber can be obtained by rotating the fiber and repeating the procedure at multiple angular positions.

Abstract: The nondestructive determination of core size of a hollow-core photonic bandgap fiber (HC-PBF) using Fabry-Perot (FP) interference is performed with an apparatus including a tunable laser source (TLS), a 1×2 single-mode (SM) coupler, an SM collimator, a six-axis translation stage, an optical detector, and an oscilloscope. The light from the TLS passes through the 1×2 SM coupler and the SM collimator to perpendicularly enter two parallel air-SiO2 interfaces of the core of the fiber and is reflected, while the TLS is tuned from one wavelength to another. Then the reflected spectrum is guided to the optical detector, where its interference intensity is converted into voltage intensity to be displayed at the oscillator and fitted with a least-squares method to obtain the distance between the two air-SiO2 interfaces. The core size of the fiber can be obtained by rotating the fiber and repeating the procedure at multiple angular positions.