
power levels. The proposed concept may open up a novel technology for compen-
sating fiber nonlinearities in optical domain.
4.6 VCSEL-BASED SLOW LIGHT DEVICES
The manipulation of the speed of light has been attracting much interest in recent
years. In particular, slow light observed in photonic crys tals, semiconductor
amplifiers, and microresonators has been studied for optical buffer memories,
optical delay lines, and so on [106–108]. Also, the slow group velocity of light
dramatically reduces the size of various optical devices such as optical amplifiers,
optical switches, and nonlinear optical devices [109, 110]. We have observed large
waveguide ...