Keithley Instruments introduces configurable laser diode test systems

April 1, 2003
1 April 2003 Cleveland, OH Lightwave--Keithley Instruments is debuting customizable test system kits for light-current-voltage characterization of laser diodes and assembled laser diode modules.

1 April 2003 Cleveland, OH--Keithley Instruments is debuting customizable test system kits for light-current-voltage (LIV) characterization of laser diodes and assembled laser diode modules (LDMs). In the new System 25 kits, Keithley takes advantage of its proven LIV measuring instruments, combines them with accessories and cables, and supplies the complete package for less than the cost of the individual components.

The System 25 kits provide up to 5A laser drive current, precision voltage measurements, two channels of photodetection, selectable photodiode detector types, optional laser diode mount, and two temperature controllers for laser cooling. The ordering process gives purchasers flexibility in selecting only essential system components, thereby avoiding the cost of unnecessary items.

All laser diodes, including edge emitters, vertical-cavity surface-emitting lasers, and tunable lasers must undergo LIV testing. The test system sweeps a forward current through the laser diode while measuring the voltage across the device and the amount of light (optical power) being emitted. Typically, collected data is displayed as a series of LIV characteristic curves. These curves can be used in laser diode research and development and by production test engineers to review device parameters that determine if a laser diode or LDM is suitable for higher level assembly. In production facilities, these tests may be performed anywhere from incoming inspection to finished LDMs mounted in higher level assemblies.

System 25 was designed to simplify and reduce the cost of creating and using LIV test systems. It eliminates the need to purchase system components separately, which may include a source-measure unit, temperature controller, integrating sphere, photodiode detector, current meter, laser diode mount, plus cabling and ancillary hardware. A system can be specified in any of 144 combinations that use Keithley Series 2400 SourceMeter Instruments, Model 2502 Fiber Alignment Photodiode Meters, Model 2510-AT Autotuning TEC controllers, Model 2500INT Integrating Spheres, and Model 85xx Laser Diode Mounts.

These combinations are selected based on the application: general purpose laser diodes, transmitter/pump lasers, or high power pump lasers. For LDMs and laser diodes in cooled mounts, one or two TEC (thermoelectric cooler) controllers can be specified for the System 25. Typically, one Model 2510-AT will be used to control an internal TEC device; a second Model 2510-AT can be added to allow for precise control of ambient test temperature using a fixture mounted TEC. The Model 2500INT two-inch integrating sphere can be specified with either silicon, germanium, or cooled InGaAs photodetectors, depending on the wavelength response needed. For laser diodes packaged in the common 14-pin butterfly package or DIL package, a Keithley Model 85xx Laser Diode Mount can be used for connection of the device under test to the test equipment. The Model 8544-TEC mount has a built-in TEC cooler for ambient temperature control.

Customized variations of the System 25 are also available by contacting a local Keithley sales representative. System 25 shipments are available four weeks after receipt of order. Pricing starts at $8,500 per system.