There are a number of advanced microphotonic devices that have reached their commercial maturity. It is interesting to point out that all these devices employ a set of generic functional blocks or subsystems that have been introduced in the previous chapters, such as:

• Fiber or waveguide couplers • SOI channel waveguides and 1 × N branches • MOEMS switches • Waveguide amplifiers • Waveguide interferometers • Waveguide Bragg gratings

Typically, each generic functional block has substantial market value on its own. They can be integrated to enable various more complex multifunctional devices. As the component library expands, more sophisticated devices can be realized at minimal additional development cost. Microphotonic device design methodology parallels the highly successful development methodology that was employed for the evolution of integrated electronic circuits.