Tong Hoang Tuan

Mid-infrared supercontinuum generation spanning 2.0 to 15.1 μm in a chalcogenide step-index fiber.

We experimentally demonstrate mid-infrared (MIR) supercontinuum (SC) generation spanning ∼2.0 to 15.1 μm in a 3 cm-long chalcogenide step-index fiber. The pump source is generated by the difference frequency generation with a pulse width of ∼170  fs, a repetition rate of ∼1000  Hz, and a wavelength range tunable from 2.4 to 11 μm. To the best of our knowledge, this is the broadest MIR SC generation observed so far in optical fibers. It facilitates fiber-based applications in sensing, medical, and biological imaging areas.

Optical parametric gain and bandwidth in highly nonlinear tellurite hybrid microstructured optical fiber with four zero-dispersion wavelengths

The parametric amplification gain and bandwidth in highly nonlinear tellurite hybrid microstructured optical fiber (HMOF) are simulated based on four wave mixing process. The fiber core and cladding materials are made of TeO(2)–Li(2)O–WO(3)–MoO(3)–Nb(2)O(5) and TeO(2)–ZnO–Na(2)O–P(2)O(5) glass, respectively. The fiber has four zero-dispersion wavelengths and the chromatic dispersion is flattened near the zerodispersion wavelengths. A broad gain bandwidth as wide as 1200 nm from 1290 to 2490 nm can be realized in the near infrared window by using a tellurite HMOF as short as 25 cm.

Fabrication of all-solid AsSe2–As2S5 microstructured optical fiber with two zero-dispersion wavelengths for generation of mid-infrared dispersive waves

We design and fabricate an all-solid chalcogenide microstructured optical fiber (MOF) with four rods in the cladding, in order to generate mid-infrared (MIR) dispersive waves (DWs). The high-index background is made of AsSe2 glass, and the four low-index rods are made of As2S5 glass. This MOF has two zero-dispersive wavelengths: ~3,720 and 4,230 nm. The propagation loss is ~1.9 dB/m at 2,000 nm, and the nonlinear coefficient is ~4 × 103 km−1 W−1 at 3,000 nm. Using a pulse of ~80 MHz and ~200 fs emitted from an optical parametric oscillator as the pump source, the resulting MIR DWs are investigated at different pump wavelengths.

Optical parametric oscillator based on degenerate four-wave mixing in suspended core tellurite microstructured optical fiber.

We report on a suspended core tellurite microstructured optical fiber (TMOF) based optical parametric oscillator (OPO). The intracavity gain is provided by the degenerate four-wave mixing (DFWM) occurred in a 1.5-m-long TMOF synchronously pumped by a mode-locked picosecond erbium-doped fiber laser. The oscillated signal can be generated from 1606 nm to 1743.5 nm, and the idler can be emited from 1526.8 nm to 1395 nm by adjusting the pump wavelength from 1565.4 nm to 1551 nm. A total intenal conversion efficiency of -17.2 dB has been achieved.

Supercontinuum generation in the normal dispersion regime using chalcogenide double-clad fiber

We experimentally demonstrate mid-infrared (MIR) supercontinuum (SC) generation in a 2.8-cm-long chalcogenide double-clad fiber (Ch-DCF). The Ch-DCF made of As2Se3, AsSe2, and As2S5 glasses has near-zero chromatic dispersion in the normal dispersion regime. We pump the Ch-DCF using a 200 fs pulse laser at 10 µm, and obtain MIR SC extending from 2 to 14 µm. Numerical results show that the Ch-DCF has the potential of generating a highly coherent MIR SC light source.

Highly efficient picosecond degenerate four-wave mixing in a tellurite microstructured optical fiber

Wavelength-tunable picosecond degenerate four-wave mixing was demonstrated in a tellurite microstructured optical fiber (TMOF). The zero-dispersion wavelength of the TMOF was shifted to 1570 nm by introducing a single ring of air holes in the cladding. The anti-Stokes signal sideband can be generated from 1490 to 1500 nm, and the Stokes idler sideband can emit from 1595 to 1645 nm. Because of the high nonlinearity of the TMOF and the large peak power of the picosecond pump, a maximal signal gain of 31.2 dB and an idler conversion efficiency of +35 dB were achieved.

Tellurite microstructured fiber based optical parametric amplifier

An optical parametric amplifier has been demonstrated by using a 3-m-long tellurite microstructured fiber as the gain medium. Due to the highly nonlinear property, a maximal peak gain of 90.2 dB has been achieved in the S band.

Experimental investigation of mid-infrared supercontinuum generation in chalcogenide step-index optical fibers

We experimentally investigate mid-infrared (MIR) supercontinuum (SC) generation in chalcogenide step-index optical fibers. The pump source is generated by the difference frequency generation with a pulse width of ~170 fs, a repetition rate of ~1000 Hz, and a wavelength range tunable from 2.5 to 11 μm. The wide MIR SC will be applied in sensing, medical and biological imaging areas.

Experimental observation of multiple dispersive waves emitted by multiple mid-infrared solitons in a birefringence tellurite microstuctured optical fiber

We experimentally demonstrate multiple dispersive waves (DWs) emitted by multiple mid-infrared solitons in a birefringence tellurite microstuctured optical fiber (BTMOF). To the best of our knowledge, this is the first demonstration of multiple DWs in the non-silica fibers. By using a pulse of ~80 MHz and ~200 fs emitted from an optical parametric oscillator (OPO) as the pump source, DWs and solitons are investigated on the fast and slow axes of the BTMOF at the pump wavelength of ~1800 nm. With the average pump power increasing from ~200 to 450 mW, the center wavelength of the 1st DW decreases from ~956 to 890 nm, the 2nd DW from ~1039 to 997 nm, the 3rd DW from ~1101 to 1080 nm, and the 4th DW from ~1160 to 1150 nm. Meanwhile, obvious multiple soliton self-frequency shifts (SSFSs) are observed in the mid-infrared region. Furthermore, DWs and solitons at the pump wavelength of ~1400 and 2000 nm are investigated at the average pump power of ~350 mW.

Far-detuned four-wave mixing for mid-infrared wavelength conversion in chalcogenide As2S5 suspended core fiber

The mid-infrared (MIR) range is of great interest because fundamental molecular vibrational absorption bands exist in the MIR range. In the MIR range, typically, lasing can be generated using quantum cascade lasers, cascaded Raman lasers, and optical parametric oscillators (OPOs). Recently, fiber OPOs (FOPOs) in the MIR range have received attention because of their flexibility of the parametric gain curve designing the chromatic dispersion. Chalcogenide glass is the promising candidate for MIR FOPO because of their wide transmission window and high nonlinear coefficient. In the present paper, we design the chromatic dispersion of four-hole As2S5 chalcogenide suspended core fiber (SCF), and demonstrate a far-detuned four-wave mixing (FWM) for MIR FOPO. We design the four-hole As2S5 chalcogenide SCF for far-detuned FWM using a ∼2 μm pump source. A four-hole As2S5 chalcogenide SCF which has a core diameter of 3.25 μm is fabricated using a homemade draw tower. We experimentally observed far-detuned FWM in the four-hole As2S5 chalcogenide SCF. A detuning frequency of over 80 THz is measured in 21 cm long fiber using a 2.7 ps pulse laser at 1.96 μm. The experimental observation was confirmed by numerical demonstration.