Fabrication of Er Doped Glass Films as Used in Planar Optical Waveguides
- PDF / 3,459,342 Bytes
- 8 Pages / 414.72 x 648 pts Page_size
- 31 Downloads / 162 Views
J. V. GATES, A. J. BRUCE, J. SHMULOVICH, Y. H. WONG, G. NYKOLAK, M. R. X. BARROS and R. GHOSH AT&T Bell Laboratories, Murray Hill, NJ 07974.
ABSTRACT Silica integrated optical circuits are expanding in functionality to include optically active waveguides. Traditionally, the planar optical waveguide structures include silica based glass films such as thermal oxides, phosphorous, and boron-phosphorous doped glasses. Various efforts have successfully doped conventional waveguides with Er, typically by solution doping. Material issues such as rare earth solubility and glass structure dictate that efficient optical amplifiers based on such waveguides have path lengths in excess of 10-15 cm. We have developed an alternative strategy using Er-doped soda-lime silicate glass films on silicon. The waveguide processing utilizes methods of deposition similar to those used in silicon IC technology, with modificatons in the compositions and thicknesses. In these glasses the effective solubility limits are relaxed and we have successfully fabricated short path length devices which demonstrate net gain of more than 4 dB/cm. Short path length devices offer a potential advantage in highly integrated multi-channel devices and offer an additional building block in system architectures.
INTRODUCTION Optical amplifiers continue to play an increasing role as a cost effective element in long distance optical communication. In order to penetrate deeper into the system architecture, such as advanced fiber in the local loop applications (FITL), these devices will need to be reduced in cost and satisfy new applications with larger volume demands. Most fiber amplifier systems are built using discrete bulk optical components such as splitters, taps, multiplexers, filters and pump lasers. Many of these components can be made using planar waveguide technology such as Silicon Optical Bench (SiOB) . Planar technology allows for the integration of many components onto one substrate as shown in Fig. 1. The device shown is a 1.53/1.551im multiplexer/amplified spontaneous emission filter, two pump couplers (0.98/1.55jtm), a MachZehnder filter at 1.53.Lm, a 0.98ýtm 3dB coupler, a crossover and a turn-around at 0.98g.m.
Fig. I SiOB waveguide circuit for integrated fiber-amplifier passive components. 209 Mat. Res. Soc. Symp. Proc. Vol. 392 01995 Materials Research Society
In addition to the integration of the passive components, the existing SiOB technology using silicon wafers as substrates, allows for micro-machined piece parts for the inclusion of bulk isolators, lasers, PIN photo-detectors, metalized electrical routing, wire bonding pads, and self centering soldering techniques for device alignment and attachment. The development and use of micro-machined pump laser submounts and Er-doped waveguides are synergistic with similar developments in FITL transmitter/receiver components based on SiOB waveguide technology. Integration of multiple components onto a single chip and hybridization into a common package have proven to reduce the cost of both
Data Loading...
