High-power optical burn-in
View Patent ↗Semiconductor lasers are aged to identify weak or flawed devices, resulting in improved reliability of the remaining devices. The lasers can be aged using a high-power optical burn-in that includes providing a high drive current to the lasers for a period of time, and maintaining the ambient temperature of the lasers at a low temperature. After the high-power optical burn-in, the output of the lasers can be measured to determine if the lasers are operating within specifications. Those that are not can be discarded, while those that are can be further aged using a high-temperature thermal burn-in that includes providing a drive current to the lasers while maintaining the ambient temperature of the lasers at a high-temperature.
1. A method of aging an optical signal source to determine the reliability of the optical signal source, the method comprising:
providing a first drive current to an optical signal source, the first drive current being at least three times greater than a normal operating bias current of the optical signal source;
maintaining the first drive current to the optical signal source for a first period of time, the first period of time being five hours or more; and
maintaining the ambient temperature of the optical signal source at or below a first temperature during the first period of time, the first temperature being 50 degrees Celsius or lower.
2. The method of claim 1 , further comprising, after providing the first drive current to the optical signal source for the first period of time, performing thermal burn-in on the optical signal source.
3. The method of claim 2 , wherein performing thermal burn-in on the optical signal source includes providing a second drive current to the optical signal source for a second period of time while maintaining the ambient temperature of the optical signal source at a second temperature, the second drive current being approximately two times greater than the normal operating bias current of the optical signal source.
4. The method of claim 1 , further comprising, ascertaining the reliability of the optical signal source.
5. The method of claim 4 , wherein ascertaining the reliability of the optical signal source includes:
prior to providing the first drive current to the optical signal source for the first period of time, measuring the initial optical output power of the optical signal source;
after providing the first drive current to the optical signal source for the first period of time, measuring the final optical output power of the optical signal source; and
comparing the final optical output power to the initial optical output power.
6. The method of claim 5 , wherein when the final optical output power drops at least 2% compared to the initial optical output power, the optical signal source is determined to be unreliable.
7. The method of claim 1 , wherein the first drive current is between three and four times greater than the normal operating bias current of the optical signal source.
8. The method of claim 1 , wherein the first drive current is between 150 milliamps and 240 milliamps.
9. The method of claim 1 , wherein the first period of time is approximately one-hundred hours.