Semiconductor Pumps for the Nd: YAG Laser.
Abstract
This report describes the major accomplishments and conclusions of a six-month program to develop high-power light emitting diodes suitable as pump sources for the Nd: YAG laser at room temperature. Work was concentrated on the development of the material and device technology required for zinc-diffused Ga sub (1-X) Al sub x As 25-mil-and 36-mil-diameter dome emitters. The increased current capability of these larger devices enables the achievement of higher optical output powers than are possible with conventional 18-mil-diameter dome emitters. Improved materials technology enabled the growth of the increased epitaxial layer thickness required for the larger diameter domes and enabled the growth of multilayer structures to minimize absorption losses. Optical output powers of greater than 60 mW at 500 mA with a 7% power efficiency were achieved with 25-mil-diameter dome emitters fabricated from single epitaxial layers. Quantum efficiencies of 9.5% were observed at lower currents. Optical output powers of greater than 100 mW at 750 mA with an 8% power efficiency were achieved with 36-mil-diameter dome emitters. Quantum efficiencies of 10% were achieved at lower currents. These high efficiency emitters were achieved by the use of a double epitaxial layer structure con asisting of a thin GaAlAs epitaxial layer containing the junction grown on higher bandgap thick GaAlAs epitaxial layer. However, the wavelengths of these emitters were too long and the spectral half-widths were too wide for efficient laser pumping. A detailed analysis of the experimental thermal resistance showed that 25-mil-diameter domes are optimum for maximum power for linear diode arrays.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1973
- Accession Number
- AD0913162
Entities
People
- Eugene G. Dierschke
Organizations
- Texas Instruments