Optical Devices

Abstract

Optical devices are an important part of this book for they are not peripheral to the basic development of ferroelectric memories. Not all memories will have electrical READ and electrical WRITE operations. Several researchers have already investigated electrical READ/optical WRITE FE-RAMs with the intention of using nondestructive optical READs to eliminate reset and hence greatly reduce fatigue [505, 506, 507, 508]. Optical WRITE/electrical READ devices are potential replacements for X-ray film. At present, X-ray records take a lot of hospital storage space (or are kept in patients’ homes) and are time consuming and expensive to retrieve and deliver to the doctor’s office in a timely manner. Moreover, reading X-ray films and comparing them is an art. It would be a great improvement to have these films available digitally on the PC (Personal Computer) of every doctor’s office, in high resolution (> 4 megapixel) form, with grey scales (obtained from different bias voltages), and the ability to align different X-rays and digitally subtract one from another, to show only changes in the images (e.g., tumor size). Finally, all-optical READ/WRITE memories (photonic devices) may become possible with ferroelectrics. These possibilities are discussed below.