Measurement of band structures of photonic bandgap materials by picosecond optoelectronic techniques

It is now well established that electromagnetic waves in a periodic dielectric array (photonic crystal) exhibit band structure where regions of allowed modes are separated by forbidden frequency gaps (band gaps). In this talk, we discuss the application of ultrafast optoelectronics to the measurement of band structure in two-dimensional photonic crystals. For the first time, the imaginary wave-vector dispersion in the bandgap region is measured using the coherent microwave transient spectroscopy (COMITS) technique. Also, by constructing the photonic analog of a semiconductor quantum well, we observe quantized states in the photonic band gap