Hundred-meter-scale, kilowatt peak-power, near-diffraction-limited, mid-infrared pulse delivery via the low-loss hollow-core fiber

Abstract

We report a high-power single-mode mid-infrared (MIR) pulse delivery system via anti-resonant hollow-core fiber (HCF) with a record delivery distance of 108 m. Near-diffraction-limited MIR light was transmitted by HCFs at wavelengths of 3.12–3.58 µm using a tunable optical parametric oscillator (OPO) as the light source. The HCFs were purged beforehand with argon in order to remove or reduce loss due to parasitic gas absorption (HCl, CO2, etc.). The minimum fiber loss values were 0.05 and 0.24 dB/m at 3.4–3.6 µm and 4.5–4.6 µm, respectively, with the 4.5–4.6 µm loss figure representing, to the best of our knowledge, a new low loss record for a HCF in this spectral region. At a coupling efficiency of ∼70%, average powers of 592 mW and 133 mW were delivered through 5 m and 108 m of HCF, respectively. Assuming the 120-ps duration of the MIR pulses remained constant over the low-dispersion HCF (theoretical maximum: 0.4 ps/nm/km), the corresponding calculated peak powers were 4.9 kW and 1.1 kW.

Hollow‐Core Fiber: Breaking the Nonlinearity Limits of Silica Fiber in Long‐Distance Green Laser Pulse Delivery

“…Hundreds of millions of kilometers of standard solid single-mode fiber (SMF) are installed each year to transmit relatively low power extending from the ultraviolet, through the visible and nearinfrared, and out even to the mid-infrared. [10][11][12][13][14][15] Power delivery systems on the scale of hundreds of meters have been successfully implemented in the near and mid-infrared laser wavelength region. [1,13,16] However, no long-range power delivery in the visible region has yet been demonstrated.…”

“…[10][11][12][13][14][15] Power delivery systems on the scale of hundreds of meters have been successfully implemented in the near and mid-infrared laser wavelength region. [1,13,16] However, no long-range power delivery in the visible region has yet been demonstrated. The development of HCFs for this wavelength range represents a higher fabrication challenge due to the smaller structural features.…”

“…Moreover, the loss values achievable in such fibers are falling rapidly, with the very latest fiber designs and drawing methods offering substantially lower losses than conventional fibers across most of the optical spectrum, extending from the ultraviolet, through the visible and near‐infrared, and out even to the mid‐infrared. [ 10‐15 ] Power delivery systems on the scale of hundreds of meters have been successfully implemented in the near and mid‐infrared laser wavelength region. [ 1,13,16 ] However, no long‐range power delivery in the visible region has yet been demonstrated.…”

Low-loss multi-mode anti-resonant hollow-core fibers

“…Additionally, it is established that the negative-curvature shape of the core boundary plays an important role in the reduction of the modal field overlap with the cladding material in AR-HCFs [2,3], contributing to the high laser damage threshold, low optical nonlinearity, and low waveguide dispersion. So far AR-HCFs have demonstrated successes in the delivery of high-power lasers and ultrashort pulses over long lengths [4,5].…”

Microjoule‐Level Mid‐Infrared Femtosecond Pulse Generation in Hollow‐Core Fibers

“…Another platform that is attracting growing interest in mid-IR photonics is hollow-core fibers. [13][14][15] In a hollow-core fiber, light is guided in its central hollow region, bypassing the limitations imposed by the intrinsic properties of waveguide material. It enables low-loss mid-IR transmission even in silicabased optical fibers.…”