OPTICS 2019 Abstracts

Full Papers
Paper Nr: 7

Characterization of the Bias Current Behavior in a SOA for Linearizing Amplification in a CO-OFDM System


Julio C. Ortiz-Cornejo and Jorge A. Pardiñas-Mir

Abstract: This paper presents an analysis of the semiconductor optical amplifier (SOA) on coherent optical orthogonal frequency division multiplexing system (CO-OFDM), when it is used as a booster power amplifier. The semiconductor optical amplifier is driven by their bias current injection, which control the amplification level. In this sense, this study analyses the impact of bias current change on a SOA based CO-OFDM system. It is well known that SOA is prone to nonlinear distortion when high input power is used at high gain level, because the gain saturation. In addition to the aforementioned analysis, here it is also presented three operation scenarios to characterize the performance of the system: maximum EVM equal to 20%, constant output power equal to -7 dBm, and constant SOA Gain equal to 17 dB. This let us obtain a way to optimize the SOA performance, under each scenario, controlling the bias current.

Short Papers
Paper Nr: 3

25 Gb/s NRZ and 50 Gb/s PAM-4 Transimpedance Amplifier with Active Feedback and Equalization in 90 nm CMOS Technology


Hao-Wen Hsu, Chih-Chen Peng, Jau-Ji Jou, Tien-Tsorng Shih, Yaw-Dung Wu, Shao-I Chu, Chih-Yuan Lien and Bing-Hong Liu

Abstract: In this paper, a high-linearity transimpedance amplifier (TIA) was designed in 90 nm CMOS technology. The input stage of the TIA was a regulated cascade circuit for low input impedance. The active feedback structure was used to replace the feedback resistor and to reduce the chip size. An equalizer was also used in the TIA to compensate the high-frequency response. Within input current amplitude of 1.1 mA, the total harmonic distortion of the TIA can be below 5%. The bandwidth of the TIA was about 26 GHz and its input-referred current density was below 74 pA/√Hz within the bandwidth. The TIA can be applied in 25 Gb/s non-return zero (NRZ) and 50 Gb/s (25 Gbaud) four-level pulse amplitude modulation (PAM-4) optical receivers. The power dissipation of the chip is 11.6 mW and the chip area is 0.151 mm2.

Paper Nr: 6

Noise-induced Signal Corruption in Nonlinear Fourier-based Optical Transmission System in the Presence of Discrete Eigenvalues


Maryna L. Pankratova, Anastasiia Vasylchenkova and Jaroslaw E. Prilepsky

Abstract: We present the numerical analysis of the correlation properties of the amplifier spontaneous emission (ASE) noise transformed into the nonlinear Fourier (NF) domain, addressing the noise-induced corruptions in the communication systems employing the nonlinear Fourier transform (NFT) based signal processing. In our current work we deal with the orthogonal frequency division multiplexing (OFDM) modulation of a continuous NF spectrum and account for the presence of discrete (soliton) eigenvalues. This approach is aimed at extending our previous studies that referred to the modulation of continuous NF spectrum only. The effective noise covariance functions are obtained from numerical simulations for a range of propagation distances, values of discrete eigenvalue, and different effective signal power levels. We report the existence of the correlations between the continuous and discrete parts of the NF spectrum.

Paper Nr: 10

The Reduction of 1.06-µm Emission in a Double Cladding Tellurite All-solid Photonic Bandgap Fiber Doped with Neodymium Ions


Tong H. Tuan, Kohei Suzaki, Nobuhiko Nishiharaguchi, Takenobu Suzuki and Yasutake Ohishi

Abstract: In order to take advantage of the 1.33-µm emission from 4F3/2→4I13/2 transition of Nd3+ ions to realize many potential applications in this telecommunication band, it is important to filter out the intense 1.06-µm emission from the 4F3/2→4I11/2 transition. In this work, a new tellurite all-solid photonic bandgap fiber with double cladding layer was proposed. In addition, 8 high-index rods and an Nd3+-doped core were arranged in a horizontal line and located in the center of the fiber. Numerical calculation was carried out to study the properties of the propagation modes at 0.8, 1.06 and 1.33 µm. By controlling the diameters of the core and high-index rods, it is possible to reduce the intensity of the 1.06-µm light, but maintain the intensity of the lights at 0.8 and 1.33 µm when they propagate in the fiber core.