Laser power monitoring in a heat-assisted magnetic recording device using a resistive sensor and high-frequency laser modulation

An apparatus, comprising:

• a light source configured to generate light;
• a modulator coupled to the light source and configured to modulate the light above a predetermined frequency;
• a slider configured for heat-assisted magnetic recording and to receive the modulated light;
• a resistive sensor integral to the slider and subject to heating by absorption of electromagnetic radiation and conduction of heat, the resistive sensor configured to produce a response due to absorption of the electromagnetic radiation by the resistive sensor and not from the heat conduction in response to the modulated light above the predetermined frequency;
• and
• measuring circuitry coupled to the resistive sensor and configured to measure the response of the resistive sensor due to absorbed electromagnetic radiation and not from the heat conduction.