Optical Interconnects: Transmitter Characterisation and Parameter Extraction Techniques

Student: Albert Lu

Supervisor: Aleksandar Rakic

Category: Engineering Thesis Project - Communications

As technology advances, the speed and complexity of the Integrated Circuit (IC) has increased at an unbelievable rate. However, some of the physical limitations of conventional electronic interconnects has become a bottleneck in IC development. With outstanding results in long-haul communications, Optical Interconnects (OI) provides possible solutions to many of the physical problems faced in electrical interconnects. However, the OI technology is still relatively immature and some technical issues must be addressed.

One major challenge in terms of OI development is the advancement in transmitter technology. Improving the quality of the transmitter will resolve many of the technical issues currently faced in OI implementation. In order for any progress to be made, however, more work must be done to allow a more detailed understanding of transmitter characteristics. Furthermore, methods must be developed for accurately extracting transmitter parameters.

Among the optical transmitters that are currently available, one particular type, the Vertical Cavity Surface Emitting Laser (VCSEL), had been envisioned as the most suitable for use as the transmitter for OI. VCSEL has many advantages over the traditional in-plane lasers or Light Emitting Diodes (LED), including the low cost and possibility for array manufacturing.

This thesis details the analysis of a VCSEL, including methods for extracting parameters and characterization. The characteristics investigated include the Light-Current-Voltage Analysis, the Optical Spectrum Analysis and the Beam Profile Analysis. From the results of the analysis, many VCSEL parameters can be obtained.