drlava
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- Mar 7, 2007
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Hi guys, it's been a while since I posted P-I-V plots in volume, since the large roundups a long time ago. Well, I got a new data acquisition card for the rig and built a new control board, so more data will be coming in the future.
Methods:
A few details about the testing rig: It's built on a 16 bit data acquisition card coupled to a MATLAB testing script that I wrote for diodes. It can run ramp tests at almost any current increment resolution, run lifetime tests, automatic cycling, and other tests. The ramp tests that you see me produce are all automatic tests with precise steps, typically in 2.5 or 5 mA increments. The voltage measurements are made differentially right at the diode pins, so the most accurate representation of the diode voltage is recorded. Laser power is recorded via RS232 data feed from a calibrated Scientech 365 power meter, with its head in a stabilizing isoperibol chamber. The diode temperature is kept low via an oversized CPU cooler attached to the mounting rig. Thanks goes to Steve over at ***************** for contributing the diodes tested here. He is in the process of having all of the diode and sled lines that he sells P-I-V tested for quality assurance, and will be posting plots on the data pages.
Results:
These tests were done on two different SF-AW210 diodes, using aixiz type 'blu' ar-coated glass lens assemblies. With these assemblies, the output power was 5% higher than standard open-aperture aixiz plastic.
Diode 1:
Diode 2:
As you can see, the two diodes track each other almost exactly, however diode 2 failed at 275mA with a power output of 325mW. Diode 1 has a noticeably higher Vf than diode 2, however it remains to be seen if this is indicative of higher capability. In the coming weeks I expect to be able to do lifetime burn-in tests to see at which point power output 'sagging' occurs, along with GGW comparisons and hopefully a 12x test or two. Hey, who wants to contribute to another 12x testing fund? You'll get the detailed results right here on the forum
Methods:
A few details about the testing rig: It's built on a 16 bit data acquisition card coupled to a MATLAB testing script that I wrote for diodes. It can run ramp tests at almost any current increment resolution, run lifetime tests, automatic cycling, and other tests. The ramp tests that you see me produce are all automatic tests with precise steps, typically in 2.5 or 5 mA increments. The voltage measurements are made differentially right at the diode pins, so the most accurate representation of the diode voltage is recorded. Laser power is recorded via RS232 data feed from a calibrated Scientech 365 power meter, with its head in a stabilizing isoperibol chamber. The diode temperature is kept low via an oversized CPU cooler attached to the mounting rig. Thanks goes to Steve over at ***************** for contributing the diodes tested here. He is in the process of having all of the diode and sled lines that he sells P-I-V tested for quality assurance, and will be posting plots on the data pages.
Results:
These tests were done on two different SF-AW210 diodes, using aixiz type 'blu' ar-coated glass lens assemblies. With these assemblies, the output power was 5% higher than standard open-aperture aixiz plastic.
Diode 1:
Diode 2:
As you can see, the two diodes track each other almost exactly, however diode 2 failed at 275mA with a power output of 325mW. Diode 1 has a noticeably higher Vf than diode 2, however it remains to be seen if this is indicative of higher capability. In the coming weeks I expect to be able to do lifetime burn-in tests to see at which point power output 'sagging' occurs, along with GGW comparisons and hopefully a 12x test or two. Hey, who wants to contribute to another 12x testing fund? You'll get the detailed results right here on the forum
