Input Extinction Ratio Research Articles

Limits on High Bit Rate Wavelength Reuse Using Ultralong Semiconductor Optical Amplifier

Amplitude data erasure for wavelength reuse using an ultralong semiconductor optical amplifier (UL-SOA) in saturation is demonstrated for optical carriers modulated up to 56 Gb/s (NRZ). The erasing performance efficiencies with different input bit rates are presented, as well as the influences of parameters such as input (amplitude) extinction ratio, optical power, wavelength, and UL-SOA bias current. Bit error rate (BER) curves show that the remodulated (upstream) signal has enough quality to be applied in wavelength division multiplexing-passive optical networks (WDM-PON) systems, when very high bit rates or high input extinction ratio are needed and spectral broadening in the erased carrier could be accepted.

10-Gbps, 5.3-mW Optical Transmitter and Receiver Circuits in 40-nm CMOS

We describe transmitter and receiver circuits for a 10-Gbps single-ended optical link in a 40-nm CMOS technology. The circuits are bonded using low-parasitic micro-solder bumps to silicon photonic devices on a 130-nm SOI platform. The transmitter drives oval resonant ring modulators with a 2-V swing and employs static thermal tuners to compensate for optical device process variations. The receiver is based on a transimpedance amplifier (TIA) with 4-kΩ gain and designed for an input power of - 15 dBm, a photodiode responsivity of 0.7 A/W, and an input extinction ratio of 6 dB. It employs a pair of interleaved clocked sense-amplifiers for voltage slicing and uses a DLL with phase adjustment for centering the clock in the data eye. Periodic calibration allows for adjustment of both voltage and timing margins. At 10 Gbps, the transmitter extinction ratio exceeds 7 dB and, excluding thermal tuning and laser power, it consumes 1.35 mW. At the same datarate, the receiver consumes 3.95 mW. On-chip PRBS generators and checkers with 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">31</sup> -1 sequences confirm operation at a BER better than 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup> .

Extinction ratio improvement by an advanced NOLM setup

We present a nonlinear optical loop mirror (NOLM)-based setup which is optimized for regeneration of signals with a poor extinction ratio caused by, e.g., high powered ghost pulses. In a conventional NOLM, the improvement of the extinction ratio is limited by the input extinction ratio or insufficient amplitude jitter reduction. These limitations can be overcome by an additional directional phase shifter. According to numerical simulation, the extinction ratio can be improved from 6 dB up to several 10 dB.

Experimental and theoretical investigation on novel all-optical logic AND gates

A novel scheme based on cross-gain modulation in cascaded single-port-coupled se miconductor optical amplifier(SOA) is studied theoretically and experimentally. Theoretical model for the single-port-coupled SOA is established for theoretical simulation and performance evaluation.The 10Gb/s all-optical logic AND operatio n has been demonstrated theoretically and experimentally. A parameter is exploit ed to evaluate the output performance. Results show that the output performance is tightly related to input power and input extinction ratio. Theoretical calcul ation results are in agreement with the experimental results.

Analysis of semiconductor optical amplifier based double-stage all-optical wavelength converter with improved extinction ratio

We theoretically study the temporal dynamics of a semiconductor optical amplifier (SOA) based double-stage wavelength converter in co-propagative configuration. The impact of the SOA number in the device is analyzed. In this work, we are concerned with the gain recovery time shortening while keeping a low level of noise. We also study the pump and probe power influence on a 10 Gbit/s NRZ sequence output extinction ratio and undertake a systematic study when varying the input extinction ratio.

All-optical subcarrier labeling based on the carrier suppression of the payload

We report on a new approach to all-optical subcarrier labeling based on sideband generation through carrier-suppression of the payload. The experimental transmission over 50-km standard fiber of a 10-Gb/s payload data multiplexed with a synchronized 1.25-Gb/s subcarrier label is carried out with less than 1-dB receiver power penalty, clearly demonstrating the feasibility of this sideband optical labeling scheme. The requirements to the modulation index and dc bias along with the limitation of the input extinction ratio are discussed.

Demonstration of extinction ratio improvement from 2 to 9 dB and intensity noise reduction with the MZI-GCSOA all-optical 2R regenerator

In this letter, we experimentally demonstrate improved static and dynamic characteristics of the all-optical 2R regenerator based on a Mach-Zehnder interferometer with gain-clamped semiconductor optical amplifiers. A true digital-like optical decision characteristic with an adjustable decision threshold has been found. A tremendous noise suppression at the logic 0 and a large improvement in the extinction ratio have been obtained even for a very deteriorated input signal with small extinction ratio at a bit rate of 2.488 Gb/s. An 8-dB improvement in extinction ratio can be achieved for an input extinction ratio of 5- and 7-dB improvement for an input extinction ratio of 2 dB. Furthermore, a good regeneration is achieved over a broad wavelength range of 20 nm.

All-optical 2R regeneration based on interferometricstructure incorporating semiconductor optical amplifiers

All-optical 2R regeneration in an SOA-based interferometric Michelson structure using a novel technique is experimentally demonstrated. An output extinction ratio of /spl sim/10 dB is measured for an input extinction ratio of 6 dB and a noise suppression capability of /spl sim/4.5 dB is obtained, clearly demonstrating the feasibility of this technique.