Simulation and geometrical design of multi-section tapered semiconductor optical amplifiers at 1.57 µm

Fully integrated semiconductor master-oscillator power-amplifiers (MOPA) with a tapered power amplifier are attractive sources for applications requiring high brightness. The geometrical design of the tapered amplifier is crucial to achieve the required power and beam quality. In this work we investigate by numerical simulation the role of the geometrical design in the beam quality and in the maximum achievable power. The simulations were performed with a Quasi-3D model which solves the complete steady-state semiconductor and thermal equations combined with a beam propagation method. The results indicate that large devices with wide taper angles produce higher power with better beam quality than smaller area designs, but at expenses of a higher injection current and lower conversion efficiency.

Module optical analyzer: Identification of defects on the production line

The usefulness of the module optical analyzer when identifying module defects on production line is presented in this paper. Two different case studies performed with two different kind of CPV modules are presented to show the use of MOA both in IES-UPM and Daido Steel facilities.

Optical grooming switch with regenerative functionality for transparent interconnection of networks

We demonstrate a regenerative optical grooming switch for buffer-less interconnection of metro/access and metro/core ring networks with switching functionality in time, space and wavelength domain. Key functionalities of the router are the traffic aggregation with time-slot interchanging (TSI) functionality, the WDM-to-ODTM multiplexing and the OTDM-to-WDM demultiplexing of high-speed channel into lower bit-rate tributaries as well as multi-wavelength all-optical 2R regeneration of several higher-speed signals. BER and Q-factor measurements of different switching scenarios show excellent performance with no error floor and Q-factors above 21 dB.

Repetition rate multiplication by phase-only filtering with multi-cavity optical structures

We propose several all-pass spectrally-periodic optical structures composed of simple optical cavities for the implementation of repetition rate multipliers of periodic pulse train with uniform output train envelope by phase-only filtering, and analyze them in terms of robustness and accuracy.

Channel estimation and compensation in chromatic dispersion limited optical fast OFDM systems

We experimentally investigate the channel estimation and compensation in a chromatic dispersion (CD) limited 20Gbit/s optical fast orthogonal frequency division multiplexing (F-OFDM) system with up to 840km transmission. It is shown that symmetric extension based guard interval (GI) is required to enable CD compensation using one-tap equalizers. As few as one optical F-OFDM symbol with four and six pilot tones per symbol can achieve near-optimal channel estimation and compensation performance for 600km and 840km respectively.

Scaling the Advantages of Intra-channel Nonlinearity Compensation in Future Flexible Optical Networks

We report that, contrary to common perception, intra-channel nonlinearity compensation offers significant improvements of up to 4dB, in nonlinear tolerance (Q-factor), in a flexible traffic scenario, and further improvements with increasing local link dispersion, for an optical transport network employing flexible 28Gbaud PM-mQAM transponders.

Formation and characterization of ultra-sensitive surface plasmon resonance sensor based upon a nano-scale corrugated multi-layered coated D-shaped optical fiber

We present experimental results on the performance of a series of coated, D-shaped optical fiber sensors that display high spectral sensitivities to external refractive index. Sensitivity to the chosen index regime and coupling of the fiber core mode to the surface plasmon resonance (SPR) is enhanced by using specific materials as part of a multi-layered coating. We present strong evidence that this effect is enhanced by post ultraviolet radiation of the lamellar coating that results in the formation of a nano-scale surface relief corrugation structure, which generates an index perturbation within the fiber core that in turn enhances the coupling. We have found reasonable agreement when we modeling the fiber device. It was found that the SPR devices operate in air with high coupling efficiency in excess of 40 dB with spectral sensitivities that outperform a typical long period grating, with one device yielding a wavelength spectral sensitivity of 12000 nm/RIU in the important aqueous index regime. The devices generate SPRs over a very large wavelength range, (visible to 2 mu m) by alternating the polarization state of the illuminating light.

RZ-DPSK transmission at 80 Gbit/s channel rate using in-line semiconductor optical amplifiers

We numerically demonstrate the feasibility of return-to-zero differential phase-shift keying transmission at 8.0 Gbit/s channel rate using cascaded in-line semiconductor optical amplifiers.

RZ-DPSK transmission at 80 Gbit/s channel rate using in-line semiconductor optical amplifiers

We numerically demonstrate the feasibility of return-to-zero differential phase-shift keying transmission at 80 Gbit/s channel rate using cascaded in-line semiconductor optical amplifiers.

RZ-DPSK transmission at 80 Gbit/s channel rate using in-line semiconductor optical amplifiers

We numerically demonstrate the feasibility of return-to-zero differential phase-shift keying transmission at 80 Gbit/s channel rate using cascaded in-line semiconductor optical amplifiers.

Expressions for the nonlinear transmission performance of multi-mode optical fiber

We develop an analytical theory which allows us to identify the information spectral density limits of multimode optical fiber transmission systems. Our approach takes into account the Kerr-effect induced interactions of the propagating spatial modes and derives closed-form expressions for the spectral density of the corresponding nonlinear distortion. Experimental characterization results have confirmed the accuracy of the proposed models. Application of our theory in different FMF transmission scenarios has predicted a ~10% variation in total system throughput due to changes associated with inter-mode nonlinear interactions, in agreement with an observed 3dB increase in nonlinear noise power spectral density for a graded index four LP mode fiber. © 2013 Optical Society of America.

RZ-DPSK transmission at 80 Gbit/s channel rate using in-line semiconductor optical amplifiers

We numerically demonstrate the feasibility of return-to-zero differential phase-shift keying transmission at 8.0 Gbit/s channel rate using cascaded in-line semiconductor optical amplifiers.

RZ-DPSK transmission at 80 Gbit/s channel rate using in-line semiconductor optical amplifiers

We numerically demonstrate the feasibility of return-to-zero differential phase-shift keying transmission at 80 Gbit/s channel rate using cascaded in-line semiconductor optical amplifiers.