Abstract:The first demonstration of a hollow core photonic bandgap fiber (HC-PBGF) suitable for high-rate data transmission in the 2 µm waveband is presented. The fiber has a record low loss for this wavelength region (4.5 dB/km at 1980 nm) and a >150 nm wide surface-mode-free transmission window at the center of the bandgap. Detailed analysis of the optical modes and their propagation along the fiber, carried out using a time-of-flight technique in conjunction with spatially and spectrally resolved (S 2 ) imaging, provides clear evidence that the HC-PBGF can be operated as quasi-single mode even though it supports up to four mode groups. Through the use of a custom built Thulium doped fiber amplifier with gain bandwidth closely matched to the fiber's low loss window, error-free 8 Gbit/s transmission in an optically amplified data channel at 2008 nm over 290 m of 19 cell HC-PBGF is reported.

Abstract:We show for the first time 100 Gbit/s total capacity at 2 µm waveband, using 4 × 9.3 Gbit/s 4-ASK Fast-OFDM direct modulation and 4 × 15.7 Gbit/s NRZ-OOK external modulation, spanning a 36.3 nm wide wavelength range. WDM transmission was successfully demonstrated over 1.15 km of low-loss hollow core photonic bandgap fiber (HC-PBGF) and over 1 km of solid core fiber (SCF). We conclude that the OSNR penalty associated with the SCF is minimal, while a ~1-2 dB penalty was observed after the HC-PBGF probably due to mode coupling to higher-order modes. 594-596 (2011).

Abstract-The 2-µm wave band is emerging as a potential new window for optical telecommunications with several distinct advantages over the traditional 1.55µm region. First of all, the Hollow-Core Photonic Band Gap Fiber (HC-PBGF) is an emerging transmission fiber candidate with ultra-low nonlinearity and lowest latency (0.3% slower than light propagating in vacuum) that has its minimum loss within the 2-µm wavelength band. Secondly, the Thulium-doped fiber amplifier that operates in this spectral region provides significantly more bandwidth than the Erbium-doped fiber amplifier. In this paper we demonstrate a single-channel 2-µm transmitter capable of delivering >52 Gbit/s data signals, which is twice the capacity previously-demonstrated. To achieve this we employ discrete multi-tone (DMT) modulation via direct current modulation of a Fabry-Perot semiconductor laser. The 4.4-GHz modulation bandwidth of the laser is enhanced by optical injection locking, providing up to 11 GHz modulation bandwidth. Transmission over 500-m and 3.8-km samples of HC-PBGF is demonstrated.

Herein is reported the development of a new process to manufacture (S)-pregabalin. The method comprises six steps, run under the catalysis of a recyclable polymer bound phase transfer catalyst, and afforded (S)-pregabalin in overall 54% yield, starting from building blocks acetylacetone, isovaleraldehyde, and nitromethane.

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A discrete-mode laser diode fabricated in the InGaAs/InP multiple quantum-well system and emitting single mode at λ = 2 μm is reported. The laser had an ex-facet output power >5 mW at 25°C and the laser operated mode-hop free in the temperature range −5°C-55°C.Index Terms-Mid-infrared sources, semiconductor laser, single-mode laser, strained quantum-well.

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