On wafer laser stability control for heat-assisted magnetic recording
An apparatus includes a substrate. A laser is formed on a non-self supporting structure and bonded to the substrate. A waveguide is deposited proximate the laser. The waveguide is configured to communicate light from the laser to a near-field transducer that directs energy resulting from plasmonic excitation to a recording medium. A light detector is configured to detect an amount of light. At least one laser heater is disposed proximate the laser. A controller is configured to control current supplied to the at least one heater based on the detected amount of light.
1. An apparatus, comprising:
a substrate;
a laser formed on a non-self supporting stricture and bonded to the substrate;
a waveguide deposited proximate the laser, the waveguide configured to communicate light from the laser to a near-field transducer that directs energy resulting from plasmonic excitation to a recording medium;
a light detector configured to detect an amount of light fluctuation;
at least one laser heater disposed proximate the laser; and
a controller configured to:
determine if the amount of light fluctuation is greater than or equal to about 1%;
control current supplied to the at least one heater if it has been determined that the amount of light fluctuation is greater than or equal to about 1%.
2. The apparatus of claim 1 , wherein the light detector is configured to detect the amount of light fluctuation while writing data to the recording medium.
3. The apparatus of claim 1 , wherein the controller is configured to determine that a laser mode hop has occurred based on the detected amount of light fluctuation.
4. The apparatus of claim 3 , wherein the controller is configured to determine that a laser mode hop has occurred if the detected light fluctuation is greater than 1%.
5. The apparatus of claim 1 , wherein the controller is disposed in a recording head.
6. The apparatus of claim 1 , wherein the light detector is a photodetector.
7. The apparatus of claim 1 , wherein the light detector is a bolometer.
8. The apparatus of claim 1 , wherein the controller is configured to control current supplied to the at least one heater to bring the temperature of the laser to a predetermined temperature range.
9. A system, comprising:
a recording head comprising:
a substrate;
a laser formed on a non-self supporting structure and bonded to the substrate;
a waveguide deposited proximate the laser, the waveguide configured to communicate light from the laser to a near-field transducer that directs energy resulting from plasmonic excitation to a recording medium; and
a light detector configured to detect an amount of light fluctuation;
at least one laser heater disposed proximate the laser; and
a controller configured to:
determine if the amount of light fluctuation is greater than or equal to about 1%;
control current supplied to the at least one if it has been determined that the amount of light fluctuation is greater than or equal to about 1%.
10. The system of claim 9 , wherein the light detector is configured to detect the amount of light fluctuation while writing data to the recording medium.
11. The system of claim 9 , wherein the controller is configured to determine that a laser mode hop has occurred based on the detected amount of light fluctuation.
12. The system of claim 11 , wherein the controller is configured to determine that a laser mode hop has occurred if the detected amount of light fluctuates by at least 1%.
13. The system of claim 9 , wherein the controller is disposed in a recording head.
14. The system of claim 9 , wherein the light detector is a photodetector.
15. The system of claim 9 , wherein the light detector is a bolometer.
16. The system of claim 9 , wherein the controller is configured to control current supplied to the at least one heater to bring the temperature of the laser to a predetermined temperature range.
17. A method comprising:
detecting an amount of light fluctuation proximate a waveguide of a recording head;
determining whether the amount of light fluctuation detected is greater than or equal to about 1%;
if it is determined that the amount of light fluctuation detected is greater than or equal to about 1%, adjusting a current provided to a laser heater for an on-wafer laser of the recording head.
18. The method of claim 17 , wherein detecting the amount of light fluctuation proximate the waveguide comprises detecting the amount of light proximate the waveguide during a writing operation of the recording head.
19. The method of claim 17 further comprising determining that a laser mode hop has occurred if it is determined that the amount of light fluctuation detected is greater than or equal to the threshold.
20. The method of claim 17 , wherein adjusting the current provided to a laser heater for an on-wafer laser of the recording head comprises adjusting the current supplied to the laser heater to bring the temperature of the laser to a predetermined temperature.