Recent progress on uncooled 1.3-μm lasers for loop applications

Abstract

The uncooled laser transmitter is cheaper and more reliable than a thermo-electrically cooled laser transmitter because of its simplicity in packaging. The low-cost, highly reliable uncooled laser may have a strong influence on pushing fiber deployment closer to the home. For loop applications, the laser transmitter must operate reliably over the temperature range of −40 to 85°C. It is rather difficult to make high-performance uncooled lasers in the long-wavelength region (1.3–1.55 μm) because the laser temperature performance suffers from Auger recombination in the low-band-gap material and from poor electron confinement resulting from the small conduction-band offset (ΔEc = 0.4ΔEg) of the GaxIn1−xAsyP1−y/InP material system. We discuss a design for uncooled lasers that minimizes the changes in both threshold current and slope efficiency over a temperature range of −40 to 85°C.2 The design is quite different from that of low-threshold-current lasers.