Cutting Edge Optronics has developed a family of arrays for high-power QCW operation. These arrays are built using CTE-matched heat sinks and hard solder in order to maximize the reliability of the devices.

A summary of a recent life test is presented in order to quantify the reliability of QCW arrays and associated laser gain modules. A statistical analysis of the raw lifetime data is presented in order to quantify the data in such a way that is useful for laser system designers.

The life tests demonstrate the high level of reliability of these arrays in a number of operating regimes. For single-bar arrays, a MTTF of 19.8 billion shots is predicted. For four-bar samples, a MTTF of 14.6 billion shots is predicted. In addition, data representing a large pump source is analyzed and shown to have an expected lifetime of 13.5 billion shots. This corresponds to an expected operational lifetime of greater than ten thousand hours at repetition rates less than 370 Hz.

Cutting Edge Optronics (CEO) manufactures laser diode arrays based on two main types of technology, hard solder (CEO Golden Bullets) and soft solder (CEO Silver Bullets). Golden Bullets are state-of-the-art and are built using gold-tin solder and heat sinks that have the same CTE (coefficient of thermal expansion) as the laser diode bar. As a result, arrays built from Golden Bullets are extremely resistant to solder creep and other failure modes that result from thermal expansion and contraction in the array.

Numerous laser media exist with absorption peaks that are too narrow to make use of standard laser diode pump arrays with emission widths of 2-3 nm. For these absorption peaks (such as Nd:YAG at 885nm, Nd:YVO4 at 880nm, and Yb:YAG at 969nm), laser diode pump arrays with narrower emission spectra are highly beneficial.

Cutting Edge Optronics has developed a process for building high-power laser diode arrays with narrow emission spectra by adding Volume Bragg Gratings during the packaging process. These arrays emit with a spectral width of approximately 0.5nm (FWHM), and are available with output powers ranging from tens of watts to several kilowatts. Experimental data is presented in this technical note for arrays operating at up to 100W per bar (CW).

© 2011 Northrop Grumman Systems Corporation – All Rights Reserved

Cutting Edge Optronics (CEO) has recently developed high-power laser diode arrays specifically for long-life operation in quasi-CW applications. These arrays feature a new epitaxial wafer design that utilizes a large optical cavity and are packaged using AuSn solder and CTE-matched heat sinks.

This work focuses on life test matrix of multiple epitaxial structures, multiple wavelengths, and multiple drive currents.  Particular emphasis is given to the 80x and 88x wavelength bands running at 100-300 Watts per bar. Reliable operating points are identified for various applications including range finding (product lifetimes less than 1 billion shots) and industrial machining (product lifetimes greater than 20 billion shots). In addition to life test data, a summary of performance data for each epitaxial structure and each bar design is also presented.