Mid-infrared all-optical modulators based on an acetylene-filled hollow-core fiber

Abstract

We report all-optical mid-infrared phase and intensity modulators based on the photo-thermal effect in an acetylene-filled anti-resonant hollow-core fiber. Optical absorption of the control beam promotes the gas molecules to a higher energy level, which induces localized heating through non-radiative relaxation and modulates the refractive index of the gas material and hence the accumulated phase of the signal beam propagating through the hollow-core fiber. By modulating the intensity of the control beam, the phase of the signal beam is modulated accordingly. By use of a 1.53 µm near-infrared control beam, all-optical phase modulation up to 2.2π rad is experimentally demonstrated at the signal wavelength of 3.35 µm. With the phase modulator placed in one arm of a Mach-Zehnder interferometer, intensity modulation with on-off ratio of 25 dB is achieved. The gas-filled hollow-core-fiber modulators could operate over an ultra-broad wavelength band from near-to midinfrared and have promising application in mid-infrared photonic systems.

Mid-infrared computational temporal ghost imaging

“…The temporal resolution of the downconversion computational TGI is determined by the temporal resolution of the preprogrammed temporal patterns modulated on the 1.5 μm light. Using a 1.5 μm telecom electro-optic modulator with modulation bandwidth up to 40 GHz, one can increase the speed of the temporal object up to tens of Gbps at mid-infrared, and we therefore anticipate the proposed mid-infrared computational TGI scheme to provide new possibilities to characterize advanced high-speed mid-infrared intensity modulators 39 – 41 and enable implementing high-speed free-space optical communications in the 3-5 μm and 8-14 μm atmospheric transmission windows 28 , 42 even in the presence of atmospheric turbulence 43 (see Supplementary note S5 for a possible schematic of high-frequency signal transmission and secure communication in the mid-infrared region using frequency downconversion computational TGI). Furthermore, applying recently developed near-infrared programmable temporally structured pulses 34 in the frequency downconversion process, computational TGI with temporal resolution down to the sub-ps level could lead to a new generation of scan-free pump-probe ghost imaging for the study of ultrafast dynamics in the mid-infrared spectral region such as e.g.…”

Wearable and interactive multicolored photochromic fiber display

“…Various luminous weaving patterns are displayed by controlling and adjusting the brightness of the specific light source at the end of the fiber. Furthermore, when combined with other sensing or image input elements 43 , it can achieve imperceptible, customizable, and expandable user display and interactive interfaces on pure textile products, paving the way for natural and interactive information display in daily textile products.…”

Mid-infrared optical modulator enabled by photothermal effect

“…Now, writing in Light: Advanced Manufacturing, a sister journal of Light: Science & Applications, Prof. Wei Jin and his team from the Hong Kong Polytechnic University reported an experimental realization of a novel MIR optical modulator enabled by the photothermal effect in an acetylene-filled anti-resonant hollow-core fiber (AR-HCF) 9 . With the assistance of a NIR control beam, the phase of the signal beam is observed to be directly modulated up to 2.2π rad in the MIR (3.35 μm), which extends their previous work on all-fiber phase modulator within C + L bands successfully 10 .…”