Systems and methods for performing truncated-correlation photothermal coherence tomography

A system for performing photothermal imaging, the system comprising:

• a laser;
• an infrared camera;
• and
• computer hardware including processor electronics configured 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 responsively emitted from the sample, thereby obtaining time-dependent photothermal signal data for each image pixel of the infrared camera;
• generating a truncated chirped waveform comprising a chirped sequence of truncated pulses, wherein each truncated pulse has a pulsewidth less than that of the pulses of the excitation chirped waveform, and wherein each truncated pulse is delayed by a pre-selected time delay relative to a corresponding pulse of the chirped sequence of pulses;
• cross-correlating the time-dependent photothermal signal data with the truncated chirped waveform, thereby obtaining, for each pixel of the infrared camera, time-dependent cross-correlation data;
• and
• generating image data based on the time-dependent cross-correlation data.

A method of performing acousto-thermal imaging, the method comprising:

• generating an excitation chirped waveform comprising a chirped sequence of pulses;
• controlling a high-frequency ultrasound source according to the excitation chirped waveform, such that the high-frequency ultrasound source emits a chirped sequence of ultrasound pulses;
• directing the chirped sequence of ultrasound pulses onto a sample;
• detecting, with an infrared camera, photothermal radiation emitted from the sample, thereby obtaining time-dependent photothermal signal data for each image pixel of the infrared camera;
• generating a truncated chirped waveform comprising a chirped sequence of truncated pulses, wherein each truncated pulse has a pulsewidth less than that of the pulses of the excitation chirped waveform, and wherein each truncated pulse is delayed by a pre-selected time delay relative to a corresponding pulse of the chirped sequence of pulses;
• cross-correlating the time-dependent photothermal signal data with the truncated chirped waveform, thereby obtaining, for each pixel of the infrared camera, time-dependent cross-correlation data;
• and
• generating image data based on the time-dependent cross-correlation data.

A system for performing acousto-thermal imaging, the system comprising:

• a high-frequency ultrasound source;
• an infrared camera;
• and
• computer hardware including processor electronics configured to perform operations comprising:
• generating an excitation chirped waveform comprising a chirped sequence of pulses;
• controlling the high-frequency ultrasound source according to the excitation chirped waveform, such that the high-frequency ultrasound source emits a chirped sequence of ultrasound pulses onto a sample;
• detecting, with the infrared camera, photothermal radiation responsively emitted from the sample, thereby obtaining time-dependent photothermal signal data for each image pixel of the infrared camera;
• generating a truncated chirped waveform comprising a chirped sequence of truncated pulses, wherein each truncated pulse has a pulsewidth less than that of the pulses of the excitation chirped waveform, and wherein each truncated pulse is delayed by a pre-selected time delay relative to a corresponding pulse of the chirped sequence of pulses;
• cross-correlating the time-dependent photothermal signal data with the truncated chirped waveform, thereby obtaining, for each pixel of the infrared camera, time-dependent cross-correlation data;
• and
• generating image data based on the time-dependent cross-correlation data.

A method of performing photo-acoustic imaging, the method comprising:

• generating an excitation chirped waveform comprising a chirped sequence of pulses;
• controlling a laser according to the excitation chirped waveform, such that the laser emits a chirped sequence of laser pulses;
• directing the chirped sequence of laser pulses onto a sample;
• detecting, with an ultrasound array, ultrasound waves emitted from the sample and beamforming the received ultrasound signals to obtain spatially-resolved time-dependent ultrasound signal data from the sample;
• generating a truncated chirped waveform comprising a chirped sequence of truncated pulses, wherein each truncated pulse has a pulsewidth less than that of the pulses of the excitation chirped waveform, and wherein each truncated pulse is delayed by a pre-selected time delay relative to a corresponding pulse of the chirped sequence of pulses;
• cross-correlating the spatially resolved time-dependent ultrasound signal data with the truncated chirped waveform, thereby obtaining time-dependent cross-correlation data;
• and
• generating image data based on the time-dependent cross-correlation data.

A system for performing photo-acoustic imaging, the system comprising:

• a laser;
• an ultrasound array;
• and
• computer hardware including processor electronics configured 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 an ultrasound array, ultrasound waves responsively emitted from the sample and beamforming the received ultrasound signals to obtain spatially-resolved time-dependent ultrasound signal data from the sample;
• generating a truncated chirped waveform comprising a chirped sequence of truncated pulses, wherein each truncated pulse has a pulsewidth less than that of the pulses of the excitation chirped waveform, and wherein each truncated pulse is delayed by a pre-selected time delay relative to a corresponding pulse of the chirped sequence of pulses;
• cross-correlating the spatially resolved time-dependent ultrasound signal data with the truncated chirped waveform, thereby obtaining time-dependent cross-correlation data;
• and
• generating image data based on the time-dependent cross-correlation data.