Systems and methods for performing enhanced truncated-correlation photothermal coherence tomography

A system for performing photothermal imaging, the system comprising:

• a laser;
• an infrared camera;
• and
• computer hardware comprising at least one processor and associated memory, the memory comprising instructions executable by said at least one processor to perform operations comprising:
• generating an excitation chirped waveform comprising a chirped sequence of pulses;
• controlling the laser according to the excitation chirped waveform, such that the laser emits a chirped sequence of laser pulses onto a sample;
• detecting, with the infrared camera, photothermal radiation emitted from the sample, thereby obtaining time-dependent photothermal signal data for each image pixel of the infrared camera;
• employing the excitation chirped waveform to provide a reference chirped waveform, the reference chirped waveform comprising a chirped sequence of pulses, wherein each pulse of the reference chirped waveform is delayed by a time delay relative to a corresponding pulse of the excitation chirped waveform;
• for each pixel of a plurality of pixels of the infrared camera:
• cross-correlating a respective time-dependent photothermal signal data with the reference chirped waveform and obtaining respective time-dependent cross-correlation data;
• and
• after having performed the cross-correlation, processing a time-gated subset of the time-dependent cross-correlation data to generate a cross-correlation measure;
• and
• generating image data based on the cross-correlation measures associated with the plurality of pixels.