The wide proliferation of the Internet in the mid 1990s has led to an exponential growth in bandwidth demand. The fiberoptic communications industry was faced with the option of installing more fiber and increasing the bit rate from 10 Gbit/sec in the existing communication systems by, time division multiplexing (TDM). In TDM systems, multiple signals of one wavelength are transmitted through a single fiber but are distinguished from each other by specific time intervals. That option was not economically viable. Wavelength division multiplexing (WDM) emerged as the new technology that increases the capacity of existing fiber by sending multiple (multiplexing) wavelengths down one fiber. The total bandwidth per fiber is the sum of the bit rate of each wavelength. Systems have been built with up to 128 wavelengths per fiber. There are several competing technologies that are employed for multiplexing and demultiplexing such as thin film interference filters, fiber Bragg gratings, and arrayed waveguide gratings. While WDM has kept up with the increase in bandwidth demand, fiberoptic communication systems still rely on optical-to-electrical conversion for switching purposes. This leads to inflexibility of the systems, increased maintenance, and high costs. There exists a great need to have an all-optical network. Recent developments in micro-electro mechanical systems (MEMS) provide a great promise towards making that a reality. MEMS are nanodevices. They are often likened to integrated circuits (ICs) due to similarities in size and manufacturing methods, except ICs route electrons and MEMS can route photons. WDM filter technology has matured and has become yesterday’s news, while MEMS applications remain in development stages but near commercialization. This presentation is structured to talk about WDM filter technologies and MEMS in the context of passive and active devices respectively, with emphasis on the manufacturing processes.