We had the 30-year anniversary since a VCSEL was invented by Kenichi Iga, Tokyo Institute of Technology. We have seen various applications including datacom, sensors, optical interconnects, spectroscopy, optical storages, printers, laser displays, laser radar, atomic clock, optical signal processing and so on. A lot of unique features have been proven, low power consumption, a wafer level testing and so on. In this paper, the brief history and our recent research activities on VCSEL photonics will be reviewed. We present the wavelength engineering of VCSEL arrays for use in high speed short-reach systems, which includes the wavelength integration and wavelength control. The joint research project on ultra-parallel optical links based on VCSEL technologies will be introduced for high speed LANs of 100Gbps or higher. The small footprint of VCSELs allows us to form a densely packed VCSEL array both in space and in wavelength. The wavelength engineering of VCSELs may open up ultra-high capacity networking. Highly controlled multi-wavelength VCSEL array and novel multi-wavelength combiners are developed toward Tera-bit/s-class ultrahigh capacity parallel optical links. In addition, the MEMS-based VCSEL technology enables widely tunable operations. We demonstrated an “athermal VCSEL” with avoiding temperature controllers for uncooled WDM applications. In addition, new functions on VCSELs for optical signal processing are addressed. We present an optical nonlinear phase shifter based on a VCSEL saturable absorber and the tunable optical equalization function.
Also, highly reflective periodic mirrors commonly used in VCSELs enables us to manipulate the speed of light. This new scheme provides us ultra-compact intensity modulators, optical switches and so on for VCSEL-based photonic integration. Also, this paper explores plasmonic VCSELs.