SIMPLE INTERFEROMETRIC MICROSCOPY FOR IN-SITU REAL-TIME 2-DIMENSIONALOBSERVATION OF CRYSTAL-GROWTH

We have developed a simple interferometric microscope suitable for in situ observation of crystal growth. The device consists of a light emi tting diode (LED) light source, a slightly modified microscope, and a charge coupled device (CCD) camera, all of which are inexpensive and c ommercially available. In addition to information on a standard 2D ima ge from a CCD camera, this system displays interference fringes that e nable one to map the temporal evolution of the distribution of thickne ss in real time, practically allowing 3D observation of growing crysta ls. LED light of a relatively low coherence can preferentially project a depth distribution of thin growing crystals as a fringe pattern, ef fectively suppressing parasitic interference induced by stray beams re flected off optical components. This device is as easy to use as a con ventional microscope and can be routinely applied to observe a growth of zeolite crystals in a pressurized hot solution cell. (C) 1996 Ameri can Institute of Physics.