Thermal management of laser diode mode hopping for heat assisted media recording
A method and apparatus provide for determining a temperature at a junction of a laser diode when the laser diode is operated in a lasing state that facilitates heat-assisted magnetic recording, comparing the junction temperature and an injection current supplied during the lasing state to stored combinations of junction temperature and injection current, and determining a likelihood of mode hopping occurring for the laser diode during the lasing state based on the comparison to stored combinations of junction temperature and injection current.
1. An apparatus, comprising:
a slider configured to facilitate heat assisted magnetic recording (HAMR);
a laser diode disposed in the slider;
a read element and a write element respectively situated at an air bearing surface (ABS) of the slider;
a near-field transducer (NFT) situated at the ABS proximate the write element;
an optical waveguide configured to couple light from the laser diode to the NFT; and
a heater arrangement disposed in, along, or adjacent the laser diode and configured to heat a junction of the laser diode during one or both of at least a portion of the non-lasing state and at least a portion of the lasing state of the laser diode.
2. The apparatus of claim 1 , wherein the heater arrangement is configured to heat the junction of the laser diode during at least the portion of the non-lasing state and at least the portion of the lasing state of the laser diode.
3. The apparatus of claim 1 , wherein the heater arrangement is disposed in the laser diode.
4. The apparatus of claim 1 , wherein the slider has a laser-in-slider (LIS) configuration.
5. The apparatus of claim 1 , comprising a temperature sensing arrangement configured to determine a temperature of a junction of the laser diode.
6. The apparatus of claim 1 , comprising:
a temperature sensing arrangement coupled to the laser diode and configured to determine a temperature of a junction of the laser diode;
wherein the temperature sensing arrangement is configured to calculate a temperature of the laser diode junction based on a voltage differential between a non-steady lasing state of the laser diode and a steady state lasing state of the laser diode.
7. The apparatus of claim 1 , comprising:
a heater control coupled to the heater arrangement; and
a laser control coupled to the laser diode;
wherein the heater control and the laser control define independently controllable circuits.
8. The apparatus of claim 1 , wherein the heater arrangement is electrically coupled to the laser diode.
9. The apparatus of claim 1 , wherein the heater arrangement comprises one or more of a diode, a resistive element, and a thermistor.
10. The apparatus of claim 1 , wherein the heater arrangement is configured to heat the laser diode junction to achieve a junction temperature associated with a reduced likelihood of laser diode mode hopping.
11. An apparatus, comprising:
a slider configured to facilitate heat assisted magnetic recording (HAMR);
a submount disposed on the slider and configured to support a laser diode;
a read element and a write element respectively situated at an air bearing surface (ABS) of the slider;
a near-field transducer (NFT) situated at the ABS proximate the write element;
an optical waveguide configured to couple light from the laser diode to the NFT; and
a heater arrangement disposed on the submount at a location in, along, or adjacent the laser diode, the heater arrangement configured to heat the junction of the laser diode during one or both of at least a portion of the non-lasing state and at least a portion of the lasing state of the laser diode.
12. The apparatus of claim 11 , wherein the heater arrangement is configured to heat the junction of the laser diode during at least the portion of the non-lasing state and at least the portion of the lasing state of the laser diode.
13. The apparatus of claim 11 , wherein the heater arrangement is disposed in the laser diode.
14. The apparatus of claim 11 , wherein the slider has a laser-on-slider (LOS) configuration.
15. The apparatus of claim 11 , comprising a temperature sensing arrangement configured to determine a temperature of a junction of the laser diode.
16. The apparatus of claim 11 , comprising:
a temperature sensing arrangement coupled to the laser diode and configured to determine a temperature of a junction of the laser diode;
wherein the temperature sensing arrangement is configured to calculate a temperature of the laser diode junction based on a voltage differential between a non-steady lasing state of the laser diode and a steady state lasing state of the laser diode.
17. The apparatus of claim 11 , comprising:
a heater control coupled to the heater arrangement; and
a laser control coupled to the laser diode;
wherein the heater control and the laser control define independently controllable circuits.
18. The apparatus of claim 11 , wherein the heater arrangement is electrically coupled to the laser diode.
19. The apparatus of claim 11 , wherein the heater arrangement comprises one or more of a diode, a resistive element, and a thermistor.
20. The apparatus of claim 11 , wherein the heater arrangement is configured to heat the laser diode junction to achieve a junction temperature associated with a reduced likelihood of laser diode mode hopping.