We report the observation of narrow tilted lobes in the far-field emission pattern of leaky oxide-confined vertical-cavity surface-emitting lasers (VCSELs). The VCSEL cavity is surrounded by two ...selectively oxidized aperture layers, which are intentionally designed to produce a high lateral leakage of the high-order transverse modes of the vertical cavity. The device operates in the fundamental transverse mode at oxide aperture diameters below 5~\mu \text{m} and currents up to 4 and 5 mA. At higher currents or larger aperture diameters, an additional high-order transverse optical mode evolves. This mode is revealed by the appearance of a shorter wavelength emission line in the electroluminescence spectra of the device, resulting in multi-mode lasing and in the related changes in the near- and far-field patterns. In the far-field pattern, the evolution of the high-order mode is revealed by the evolution of the two overlapping emission lobes at moderate (~5°) tilt angles with respect to the normal to the surface and by the appearance of a multi-spot or a ring pattern in the CCD camera images. Most importantly, the appearance of this high-order transverse mode is accompanied by an observation of much narrower lobes in the far-field pattern observed at significantly larger tilt angles (~35°). The tilt angle and the narrow angular width of these emission lobes in the far-field spectrum are in agreement with those calculated in the 3-D cold cavity modeling of the optical modes of the device. These narrow tilted lobes revealed in this paper are the fingerprints of the leakage effect in specially designed oxide-confined VCSELs with their intensity being proportional to the optical power leaving the aperture region in the direction parallel to the surface and propagating into the oxidized region. The effect can be applied for engineering of single-mode VCSELs, coherently-coupled 2-D VCSEL arrays, laterally integrated VCSEL-photodetector chips, and VCSELs integrated to slow light waveguides, for coupled optical gates for optical computers and other types of photonic integrated circuits.
In this article, we report on energy efficient (6.2 mW/Gbit/s) transmitter and receiver assemblies capable of NRZ 80 Gbit/s and 72 Gbit/s fiber data transmission through 2 and 50 m of MMF, ...respectively. The optical link studied consisted of a 130 nm BiCMOS driver and transimpedance amplifier, ~30 GHz VCSEL, and ~27 GHz PD.
Novel trends and concepts in the design and fabrication of vertical cavity surface-emitting lasers (VCSELs) and their integration in optical networks and implementation in integrated photonics ...applications are discussed. To serve these goals and match the growing bandwidth demands, significant changes are to be implemented in the device design. New lateral leakage-mediated single-mode VCSELs, including both devices confined by oxide layers and those confined by alloy-intermixed regions, are likely to be good candidates for light sources for the data networks of the future. An overview of the records in VCSEL transmission distances and transmission speeds is discussed in this context.
Key components of the optical interconnects are the fully integrated optical transmitter and receiver subassemblies. The required features of such components include high bit rate and energy ...efficient operation in the wide range of operating conditions as well as small dimensions. In this paper, operation of the transmitter and receiver micromodules integrated with the driving electronics into the TO-can packages is demonstrated. The evaluated TOSA and ROSA 850 nm link had a convolved -3 dB bandwidth of ~ 21 GHz. Data transmission utilizing TOSA and ROSA pair up to 28 Gb/s is demonstrated in temperature range of 25°C/85°C with the nominal and up 43% reduced power consumption as well as the limited to 330 mVpp driving voltage. Results of the multiple TOSA and ROSA link measurements show limited performance spread. Finally, error-free operation up to 38 Gb/s is presented. The obtained results indicate a high potential of 850 nm VCSEL and PIN-based TO-can assemblies for the next generation of energy-efficient high bit rate optical interconnects.
We present a new bidirectional optical subassembly (BOSA) packaging method which utilizes silicon optics and mechanics to integrate a lens, a DFB laser, a monitor photodiode (MPD) and a wavelength ...division multiplexing (WDM) filter into a silicon submount. The technology enables a compact packaging form within in a single trasnsistor outline can (TO-can) for BOSA. We made most of the assembly process on a designed silicon submount wafer. The wafer scale assembly brings the advantages for handling, burn-in screening and testing in high-volume production. Our results show promising optoelectronic performance for the GPON class B+ optical network unit (ONU). The output optical power is typically above 2mW and the average responsivity above 0.8A/W with the sensitivity above -29dbm is demonstrated. The demonstrated technique provides an alternative way to fabricate of a low-cost and compact size BOSA for various potential applications.
The trend of rising performance in combination with the reduction of size is still valid in the opto-electronic technology. That implies not only higher integration of functions into the chip but ...also a miniaturization of the hybrid assembly. It is presented a micro-assembly production line which uses a wafer as basis for the assembly process with mum accuracy. This technology is well suited for volume production since several thousand micro-systems are processed and tested on one wafer
Error-free operation at and above 28 Gbit/s is demonstrated for fully integrated TO-can based 850 nm transmitter and receiver subassemblies in a broad range of driving conditions and temperatures.
This paper examines the market drivers and architectural requirements for the evolution of Access Network PON "Head-End" equipment in the FP7 PIANO+ timescales and the implications for the internal ...backplane interconnect capacities within such equipment. It then outlines the solutions proposed within the SEPIANet project to achieve these capacities and gives an interim view of the project achievements.
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