ABSTRACT
We fabricated an optical transmitter with high frequency and integrated design based on the flip-chip interconnection technique (Hi-FIT) and assisted extended reach electroadsorption modulator integrated distributed feedback (EADFB) laser (AXEL) for 200-Gbit/s/λ application. The Hi-FIT makes it possible to increase modulation bandwidth thanks to wire-free interconnection and peaking control techniques while the AXEL can increase the optical modulation output power thanks to an integrated semiconductor optical amplifier (SOA). The fabricated Hi-FIT AXEL transmitter has a 3-dB bandwidth of more than 66 GHz. We obtained clear 224-Gbit/s 4-level pulse amplitude modulation (4-PAM) eye diagrams with a chip-output optical modulation amplitude (OMA) of more than +7.9 dBm at distributed feedback (DFB) laser and SOA currents of 70 and 30 mA, respectively.
ABSTRACT
A directly modulated DFB laser (DML) array transmitter optical sub-assembly (TOSA) operating at 112 Gbit/s was fabricated for the first time. The DML array chip, which was integrated with a GND pad, and the DML array sub-assembly were designed to suppress the adjacent electrical crosstalk of the DML array TOSA. The 3-dB bandwidths of the fabricated TOSA exceeded 18 GHz. The electrical crosstalk of the TOSA was suppressed to less than -20 dB below 18GHz. Under simultaneous 4-channel 28-Gbit/s (112 Gbit/s) operation, the OTU4 mask margins were degraded by a maximum of only 6% compared with those under discrete operation. Error-free transmissions over a 10-km single-mode fiber were demonstrated for all the lanes under 112-Gbit/s operation.
ABSTRACT
We propose a novel approach for simultaneously controlling the chirp and increasing the output power of an EADFB laser by monolithically integrating a short-cavity SOA. We achieved a 40-Gbit/s 5-km SMF transmission at a wavelength of 1.55 µm by using an EADFB SOA with a lower power consumption than a stand-alone EADFB laser.
ABSTRACT
We report an athermal InP (110) optical modulator with a simple planar n-SI-n heterostructure. A symmetrical push-pull operation provides a high-extinction ratio of >25 dB over the entire C-band and zero-chirp modulation. A Mach-Zehnder optical modulator (MZM) exhibits a 3 dB-EO bandwidth of 30 GHz and 40-Gb/s NRZ high-speed modulation with wavelength and temperature insensitive operation. We also successfully demonstrate an MZM integrated twin-IQ modulator that exhibits 56-Gb/s × 2 athermal QPSK modulation at constant drive and bias voltages.
Subject(s)
Indium/chemistry , Optical Devices , Phosphines/chemistry , Microscopy , Microscopy, Electron, Scanning , Radio Waves , Signal Processing, Computer-AssistedABSTRACT
The first ultracompact transmitter optical subassembly for long-distance, beyond-100-Gbit/s data communication systems based on a monolithically integrated light source is developed. The light source consists of four InGaAlAs-based electroabsorption modulator integrated DFB lasers (EADFB lasers) and their optical multiplexer and these components are monolithically integrated on one chip, resulting in very small chip size of 2.4 × 3.3 mm2. This small chip makes it possible to reduce the size of the transmitter module. Very small transmitter optical subassemblies (TOSAs), using the chip and employing three-dimensional interconnection board, is fabricated, whose volume is only 1.82 cc. By using the TOSA, 40-Gbit/s × 4 operation with the clear eye openings up to 10-km single mode fibre transmission is demonstrated. Electrical crosstalk under the multi-lane operation is also evaluated, and the error-free transmission is achieved with the power penalty to the discrete operation of 1 dB.
ABSTRACT
A 1.3-µm, 4 × 25-Gbit/s, EADFB laser array module with large output power and low driving voltage is developed for 100GbE. A novel rear grating DFB laser is introduced to increase the output power of the laser while keeping the single mode lasing, which is desirable for a monolithic integration. Also, InGaAlAs-based electroabsorption modulators make very-low-driving-voltage operation possible due to their steep extinction curves. With the module, very clear 25-Gbit/s eye openings are obtained for four wavelengths with the driving voltage of only 0.5 V while securing the dynamic extinction ratio required by the system. These results indicate that the presented module is a promising candidate for energy-efficient future 100GbE transmitter.
