ABSTRACT
US Army Research Office, PO Box 12211, Research Triangle Park, N C 27709
1. In tro d u c tio n ....................................................... 361 2. Rare Earth E lem ents........................................................................ 362 3. Er Doping and Related L um inescence........................................ 365
3.1. Implantation of III-N F ilm s ........................................................ 366 3.2. Doping During Epitaxial Growth of III-N F i l m s .................... 369
4. Photoluminescence Excitation Spectroscopy ............................ 371 4.1. Below Bandgap Absorption........................................................ 372 4.2. Site Selective E xperim ents........................................................ 375
5. Thermal Q uench ing ........................................................................ 378 6. Phototype Devices ........................................................................ 381
6.1. Electroluminescence D e v ic e s .................................................... 381 6.2. LED-Pumped D e v ic es ................................................................ 382
7. S u m m a ry ....................................................................................... 383 R eferences....................................................................................... 383 1
Direct bandgap IH-V compound semiconductor materials have been syn thesized and effectively utilized for many optoelectronic applications [1]. Materials such as AlGaAs and InGaAsP have been epitaxially grown with great success to form light emitters and detectors operating at the primary wavelengths (0.82 /im, 1.3 /zm, and 1.54 /zm) used for optical fiber communications. For long distance communication these systems require amplifiers to boost the transmitted signal. Initially, this amplification was done at repeater stations in which the optical signal was converted into an electrical signal, amplified, and then optically regenerated. In recent years, erbium doped fiber amplifiers (EDFA) have been used to perform this amplification while keeping the signal in the optical domain. These optical amplifiers have demonstrated major improvements in link distance, data rates,
and reduced needs for signal regeneration. The intra-subshell transitions of 4f electrons in the Er3+ ions lead to a broad emission peak centered at 1.54 /xm. The development of efficient EDFAs has also resulted in increased use of wavelength division multiplexing (WDM) optical fiber communication systems at 1.54 /xm which is the region of minimum loss in silica fibers [2-4].
