Optical transmitter based on a 1.3-mu m VCSEL and a SiGe driver circuit for short-reach applications and beyond

Long-wavelength vertical-cavity surface-emitting lasers (LW-VCSELs) with emission wavelength in the 1.3-mu m region for intensity modulation (IM)/direct detection optical transmissions enable longer fiber reach compared to C-band VCSELs, thanks to the extremely low chromatic dispersion impact at that wavelength. A lot of effort has been recently dedicated to novel cavity designs in order to enhance LW-VCSELs' modulation bandwidth to allow higher data rates. Another approach to further improve VCSEL-based IM speed consists of making use of dedicated driver circuits implementing feedforward equalization (FFE). In this paper, we present a transmitter assembly incorporating a four-channel 0.13-mu m SiGe driver circuit wire-bonded to a novel dual 1.3-mu m VCSEL array. The short-cavity indium phosphide buried tunnel junction VCSEL design minimizes both the photon lifetime and the device parasitic currents. The integrated driver circuit requires 2.5-V supply voltage only due to the implementation of a pseudobalanced regulator; it includes a two-tap asymmetric FFE, where magnitude, sign, relative delay, and pulse width distortion of the taps can be modified. Through the proposed transmitter, standard single-mode fiber reach of 20 and 4.5 km, respectively, for 28- and 40-Gb/s data rate has been demonstrated with state-of-the-art power consumption. Transmitter performance has been analyzed through pseudorandom bit sequences of both 2(7)-1 and 2(31)-1 length, and the additional benefit due to the use of the driver circuit has been discussed in detail. A final comparison with state-of-the-art VCSEL drivers is also includedt

All-VCSEL based digital coherent detection link for multi Gbit/s WDM passive optical networks

We report on experimental demonstration of a digital coherent detection link fully based on vertical cavity surface emitting lasers (VCSELs) for the transmitter as well as for the local oscillator light source at the receiver side. We demonstrate operation at 5 Gbps at a 1550 nm wavelength with record receiver sensitivity of -36 dBm after transmission over 40 km standard single mode fiber. Digital signal processing compensates for frequency offset between the transmitter and the local oscillator VCSELs, and for chromatic dispersion. This system allows for uncooled VCSEL operation and fully passive fiber transmission with no use of optical amplification or optical dispersion compensation. The proposed system demonstrates the potential of multi-gigabit coherent passive optical networks with extended reach and increased capacity. Moreover, this is, to the best of our knowledge, the first demonstration of coherent optical transmission systems using a low-cost VCSEL as the local oscillator as well as for the transmitter

Malignant peripheral nerve sheath tumor of the mediastinum: A temporary aortic transection approach

Unprecedented standard single-mode fiber reach of 20km and 4.5km respectively for 28Gb/s and 40Gb/s VCSEL-based intensity-modulation/direct detection optical transmission was obtained with a low-power transmitter assembly including a 4-channel 0.13-μm SiGe driver wire-bonded to a novel 2×1 1.3pm-VCSEL array