Quantum beats in transient reflections from layered semiconductor GaSe
are observed by using the time resolved Brewster angle reflection spe
ctroscopy. The beating structure was almost 180 degrees out of phase w
ith that in photon echoes. The phase shift in the transient reflection
arises from the anisotropy of the reflection coefficient. (C) 1998 El
sevier Science B.V. All rights reserved.