3.2 Tbit/s (80 × 40 Gbit/s) phase-shaped binary transmissionover 3 × 100 km with 0.8 bit/s/Hz efficiency

50 GHz-spaced 80 × 40 Gbit/s WDM transmission over 300 km of TeraLight^TM fibre is demonstrated without polarisation demultiplexing, using the PSBT format. A record capacity of 3.2 Tbit/s is thus achieved over the C-band only, with a spectral efficiency of 0.8 bit/s/Hz     

115 Gbit/s downstream and 10 Gbit/s upstream TWDM-PON together with 11.25 Gbit/s wireless signal utilizing OFDM-QAM modulation

In this work, we propose and investigate a 115 Gbit/s (4 × 28.75 Gbit/s) downstream and 10 Gbit/s upstream time- and wavelength-division-multiplexing passive optical network (TWDM-PON) together with 11.25 Gbit/s wireless broadcasting signal using multi-band orthogonal-frequency-division-multiplexing (OFDM) modulation within 10 GHz bandwidth. Here, to compensate the power fading and chromatic dispersion in the higher frequency, we utilize a −0.7 chirp parameter Mach–Zehnder modulator (MZM) for the OFDM signal. Hence, negative power penalties of −0.3 and −0.4 dB in the downstream and broadcasting wireless signals; and power penalty of 0.3 dB in the upstream signal are measured at the bit error rate (BER) of 3.8 × 10⁻³ after 20 km standard single mode fiber transmission without dispersion compensation.     

A 2.5-Mb/s GFSK 5.0-Mb/s 4-FSK automatically calibratedΣ-Δ frequency synthesizer

This paper describes a new sigma-delta (Σ-Δ) frequency synthesizer for Gaussian frequency and minimum shift keying (GFSK/GMSK) modulation. The key innovation is an automatic calibration circuit which tunes the phase-locked loop (PLL) response to compensate for process tolerance and temperature variation. The availability of this new calibration method allows the use of precompensation techniques to achieve high data rate modulation without requiring factory calibration. The calibration method can be applied to GFSK/GMSK modulation and also M-ary FSK modulation. The PLL, including 1.8-GHz voltage controlled oscillator (VCO), Σ-Δ modulator, and automatic calibration circuit, has been implemented in a 0.6-μm BiCMOS integrated circuit. The test chip achieves 2.5 Mb/s using GFSK and 5.0 Mb/s using 4-FSK     

2.56 Tbit/s (32×80 Gbit/s) polarisation-bit-interleavedtransmission over 120 km NDSF with 0.8 bit/s/Hz spectral efficiency

Experimental results of 32×80 Gbit/s polarisation-bit-interleaved carrier-suppressed RZ transmission over 120 km of NDSF with 0.8 bit/s/Hz spectral efficiency are reported. System Q values between 6.1 and 8 (2³¹-1 pattern) were achieved with the use of distributed Raman amplification and polarisation demultiplexing     

640 Gbit/s (32×20 Gbit/s) WDM transmission with 0.4(bit/s)/Hz spectral efficiency using short-period dispersion-managedfibre

640 Gbit/s (32 channel×20 Gbit/s) WDM transmission with 0.4 (bit/s)/Hz spectral efficiency is demonstrated using short-period dispersion-managed fibre (Perfect Cable^TM). The average Q-factor was measured to be better than 18 dB after transmission over 280 km     

Design and Implementation of Open‐Loop Clock Recovery Circuit for 39.8 Gb/s and 42.8 Gb/s Dual‐Mode Operation

This paper proposes an open‐loop clock recovery circuit (CRC) using two high‐Q dielectric resonator (DR) filters for 39.8 Gb/s and 42.8 Gb/s dual‐mode operation. The DR filters are fabricated to obtain high Q‐values of approximately 950 at the 40 GHz band and to suppress spurious resonant modes up to 45 GHz. The CRC is implemented in a compact module by integrating the DR filters with other circuits in the CRC. The peak‐to‐peak and RMS jitter values of the clock signals recovered from 39.8 Gb/s and 42.8 Gb/s pseudo‐random binary sequence (PRBS) data with a word length of 2³¹?1 are less than 2.0 ps and 0.3 ps, respectively. The peak‐to‐peak amplitudes of the recovered clocks are quite stable and within the range of 2.5 V to 2.7 V, even when the input data signals vary from 150 mV to 500 mV. Error‐free operation of the 40 Gb/s‐class optical receiver with the dual‐mode CRC is confirmed at both 39.8 Gb/s and 42.8 Gb/s data rates.     

40-Gb/s OTDM to 4×10 Gb/s WDM conversion in monolithic InPMach-Zehnder interferometer module

Transformation of high bit-rate optical time-domain multiplexed (OTDM) signals into a multitude of lower bit-rate wavelength-division-multiplexed (WDM) channels is demonstrated by means of a single monolithically integrated indium phosphide Mach-Zehnder interferometer with semiconductor optical amplifiers in its arms. Full demultiplexing of 10-Gb/s OTDM signals into 4×10-Gb/s WDM channels is demonstrated. Bit-error-rate penalties are below 1.5 dB for polarization independent signal conversion throughout the 1.55-μm wavelength range     

A GaAs HBT 16×16 10-Gb/s/channel crosspoint switch

A 16×16 crosspoint switch IC has been designed and implemented in a 2-μm GaAs heterojunction bipolar transistor (HBT) technology. The IC is a strictly nonblocking switch with broadcast capability and asynchronous data paths. The IC has fully differential internal circuitry and is packaged in a custom high-speed assembly. Test results confirmed that the IC achieves a 10-Gb/s/channel (or 160-Gb/s aggregate) capacity, the highest reported to date for a 16×16 crosspoint switch IC     

Transmission of eight channels×622 Mbit/s and 15channels×155 Mbit/s using spectral encoded optical CDMA

A spectral optical code division multiple access transmission system using forward error correction is demonstrated. Matching channels are recovered error-free with 15 channels operating at 155.52 Mbit/s and up to eight channels operating at 622.08 Mbit/s     

1.28 Tbit/s (32×40 Gbit/s) WDM transmission over 2400 km ofTeraLightTM/Reverse TeraLight(C) fibres using distributedall-Raman amplification

1.28 Tbit/s capacity transmission of 32×40 Gbit/s, 100 GHz-spaced channels is demonstrated over 2400 km using distributed all-Raman amplification and electrical-TDM equipment over an optimised TeraLight^TM/Reverse TeraLight(C) dispersion map     

Cost‐Effective Transition to 40 Gb/s Line Rate Using the Existing 10 Gb/s‐Based DWDM Infrastructure

In this paper, we propose and demonstrate a cost‐effective technique to upgrade the capacity of dense wavelength division multiplexing (DWDM) networks to a 40 Gb/s line rate using the existing 10 Gb/s‐based infrastructure. To accommodate 40 Gb/s over the link optimized for 10 Gb/s, we propose applying a combination of super‐FEC, carrier‐suppressed return‐to‐zero, and pre‐emphasis to the 40 Gb/s transponder. The transmission of 40 Gb/s DWDM channels over existing 10 Gb/s line‐rate long‐haul DWDM links, including 40×40 Gb/s transmission over KT's standard single‐mode fiber optimized for 10 Gb/s achieves successful results. The proposed upgrading technique allows the Q‐value margin for a 40 Gb/s line rate to be compatible with that of 10 Gb/s.     

Multigigabit/s 1.5 μm λ/4-shifted DFB OEIC transmitterand its use in transmission experiments

Optoelectronic integrated circuit (OEIC) transmitters consisting of 1.5 μm λ/4-shifted distributed feedback (DFB) lasers and InGaAs-InAlAs MODFETs were fabricated for the first time. The entire processing requires only two organometallic vapor-phase epitaxy (OMVPE) growths, with the potential for high yield and low cost. Direct modulation of the OEIC transmitter is demonstrated for bit rates up to 10 Gb/s. A transmission experiment using the OEIC transmitter and a hybrid p-i-n/HEMT receiver is conducted at 5 Gb/s, with a sensitivity of -20 dBm and a bit-rate-distance product of 145 Gb/s-km     

1.6 Tbit/s (40 × 42.7 Gbit/s) WDM transmission over 2400 kmof fibre with 100 km dispersion-managed spans

Transmission of 40 × 42.7 Gbit/s WDM channels is demonstrated over 2400 km of fibre with 100 km amplifier spacing and 100 GHz channel spacing. Dispersion-managed fibre spans, carrier-suppressed return-to-zero modulation format and hybrid Raman/erbium-doped fibre inline amplifiers were employed to achieve a record 40 Gbit/s, WDM transmission distance with 100 km terrestrial span lengths     

40-Gb/s Series-Push-Pull Mach–Zehnder Transmitter on a Dual-Quantum-Well Integration Platform

A series-push-pull Mach–Zehnder modulator is integrated with a sampled-grating distributed Bragg reflector laser on a dual-quantum-well integration platform. The device exhibited greater than 7.8-dB extinction at 40 Gb/s with a 2.5-V drive voltage across a wavelength range of 1541–1566 nm. Bit-error-rate measurements at 10 Gb/s showed error-free operation and negative chirp.     

Alternative modulation formats in N×40 Gb/s WDM standardfiber RZ-transmission systems

A comparison of carrier-suppressed return-to-zero (CSRZ) and single sideband return-to-zero (SSB-RZ) formats is made in an attempt to find the optimum modulation format for high bit rate optical transmission systems. Our results show that CSRZ is superior to return-to-zero (RZ) and SSB-RZ with respect to signal degradation due to Kerr nonlinearities and chromatic dispersion in wavelength division multiplexing (WDM) as well as in single-channel 40-Gb/s systems over standard single-mode fibers (SSMF). It is shown that CSRZ enables a maximum spectral efficiency of approximately 0.7 (b/s)/Hz in a N×40 Gb/s WDM system with equally polarized channels. Furthermore, the CSRZ format in N×40 Gb/s WDM systems shows no further signal degradation compared to single-channel transmission     

A 6-b 1.3-Gsample/s A/D converter in 0.35-μm CMOS

A 6-b Nyquist A/D converter (ADC) that converts at 1.3 GHz is reported. Using array averaging and a wideband track-and-hold, a 6-b flash ADC achieves better than 5.5 effective bits for input frequencies up to 630 MHz at 1 Gsample/s, and five effective bits for 650-MHz input at 1.3 Gsample/s. Peak INL and DNL are less than 0.35 LSB and 0.2 LSB, respectively. This ADC consumes about 500 mW from 3.3 V at 1Gsample/s. The chip occupies 0.8-mm² active area, fabricated in 0.35-μm CMOS     

Transmission of 112 Gb/s dual-carrier DQPSK signal over 10 Gb/s-based WDM optical links

The 112 Gb/s dual-carrier differential quadrature phase shift keying (DC-DQPSK) optical transceiver, which does not need digital signal processing and coherent detection, is proposed for cost-effective 100G transport solution. In this paper, we describe upgrade schemes of 10 Gb/s-based WDM optical links by adopting 112 Gb/s DC-DQPSK transceiver, while the dispersion of the optical links is compensated 100% at each span. Method of introducing the DC-DQPSK signal into single grid of 100 GHz spaced WDM link is demonstrated. Performance sufficient for error-free operation after forward error correction is achieved over 640 km standard single mode fiber (SSMF) link. In another method, we experimentally investigate the transmission performance with co-propagating 10.7 Gb/s on-off-keying (OOK) signals over 1000 km of SSMF when the dual carriers occupy two channel grids separately. Excellent tolerance to the nonlinearities impacted by the OOK signals and low optical signal-to-noise ratio requirement are verified to demonstrate superior transmission performance in 10 Gb/s-based WDM links.     

Scalable 10 Gbit/s 4×20.25 μm CMOS/SIMOX ATM switch LSIcircuit based on distributed contention control

A scalable 10 Gbit/s 4×2 ATM switch LSI circuit has been fabricated. It employs a new distributed contention control technique that makes the LSI circuit expandable. To increase the LSI circuit throughput, 0.2 μm CMOS/SIMOX (separation by implanted oxygen) technology is used. It allows the LSI circuit to offer 221 I/O pins, an operating speed of 1.25 Gbit/s and 7 W power consumption     

A 1.2-GS/s 8-b silicon bipolar track & hold IC

An Si bipolar all-NPN track & hold (T&H) IC is presented for operation up to 2 GS/s. It is based on a switched emitter-follower design. The total harmonic distortion is less than -52.4 dB, corresponding to 8.4 b, up to 1.2 GS/s over the full Nyquist band. Fabricated in a 25 GHz f_T 0.4 μm emitter width production technology, the IC consumes 460 mW, excluding the test buffer. The transistor count is 67. The T&H lends itself as a building block for multistage high-speed 8-b A/D-converters     

140 Mbit/s receiver performance at 2.4 μm using InAsSbP detector

A 140 Mbit/s optical receiver has been demonstrated using for the first time an InAsSbP photodetector operating at room temperature and optimised for operation at 2.4 μm, close to the minimum-loss wavelength of fluoride fibre. The receiver sensitivity was measured to be -32 dBm at 140 Mbit/s and 2.4 μm