NSOM THE 4TH-DIMENSION - INTEGRATING NANOMETRIC SPATIAL AND FEMTOSECOND TIME RESOLUTION

Photonic devices are becoming the cornerstone of next generation syste ms for computing and information processing. This paper reports on the first steps in the development of methods to understand these devices with nanometric (10(-7) cm) spatial and femtosecond (10(-15) a) time resolution The basis of this achievement is the dramatic developments that have occurred in the past few pears in a new area of optics calle d near-field optics. Near-field optics is a form of lensless optics wi th a resolution that is subwavelength and which is independent of the wavelength of the light being employed. We report in this paper the tr ansmission of pulses with tens of femtosecond duration through subwave length, near-field optical elements. We also report on a femtosecond n ear-field optical right source with cross-correlating capabilities and on the growth of GaAs in the tip of micropipettes for use as an ultra fast electro-optical switch which can cross-correlate optical, electri cal, and electro-optical effects. These developments are especially re levant in the investigation of photonic devices since such devices can alter,their characteristics as a function of size in the mesoscopic r egime from just below lens-based optical resolutions to dimensions tha t approach atomic scales of similar to 1 nm (10(-7) cm). In view of th e fact that these devices and the processes that govern them also exhi bit ultrafast speeds, the combination of state of the art femtosecond laser spectroscopy with the unique features of near-field optics is a critical step in advancing our next generation understandings of such materials and structures so that their full potential in information p rocessing can be achieved.