High-density Er-implanted GaN optical memory devices

Upconversion emission has been obtained from Er-focused ion-beam (FIB) impl anted GaN. Visible green emission at the 522- and 546-nm range were excited with infrared (IR) laser sources at either 840 or 1000 nm, or with both la sers simultaneously. By implanting closely spaced patterns with the FIB, we demonstrated the concept of storing data in Er-implanted GaN. information stored as data bits consists of patterns of implanted locations as logic 1 and unimplanted locations as logic 0. The photon upconversion process in Er ions is utilized to read the stored information. This process makes use of the LR lasers to excite visible emission. The integrated upconversion emis sion power was measured to be similar to 40 pW when pumped by a 840-nm lase r at 265 mW and by a 1000-nm laser at 208 mW. Patterns as small as 0.5 mum were implanted and read. Three-dimensional optical memory based on rare-ear th-doped semiconductors could in theory approach a storage capacity of 10(1 2) bits/cm(3). (C) 2001 Optical Society of America.