Abstract: A photoacoustic remote sensing system for imaging a subsurface structure in a sample, comprising exactly one laser source configured to generate a pulsed or intensity-modulated excitation beam configured to generate ultrasonic pressure signals in the sample at an excitation location, and an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic pressure signals, an optical system configured to focus the excitation beam and the interrogation beam below a surface of the sample, a detector configured to detect the returning portion of the interrogation beam, and a processor configured to calculate an image of the sample based on a detected intensity modulation of the returning portion of the interrogation beam from below the surface of the sample.

Abstract: A photoacoustic remote sensing system (PARS) for imaging a subsurface structure in a sample, comprising one or more laser sources configured to generate a plurality of excitation beams configured to generate pressure signals in the sample at an excitation location, and a plurality of interrogation beams incident on the sample at the excitation location, a portion of the plurality of interrogation beams returning from the sample that is indicative of the generated pressure signals, an optical system configured to focus the plurality of excitation beams at a first focal point and the plurality of interrogation beams at a second focal point, the first and second focal points being below the surface of the sample, and a plurality of detectors each configured to detect a returning portion of at least one of the plurality of interrogation beams.

Abstract: A photoacoustic remote sensing system (PARS) for imaging a subsurface structure in a sample, comprising one or more laser sources configured to generate a plurality of excitation beams configured to generate pressure signals in the sample at an excitation location, and a plurality of interrogation beams incident on the sample at the excitation location, a portion of the plurality of interrogation beams returning from the sample that is indicative of the generated pressure signals, an optical system configured to focus the plurality of excitation beams at a first focal point and the plurality of interrogation beams at a second focal point, the first and second focal points being below the surface of the sample, and a plurality of detectors each configured to detect a returning portion of at least one of the plurality of interrogation beams.

Abstract: A method for visualizing details in a sample including directing an excitation beam to an excitation location below a surface of the sample, to generate signals in the sample; directing an interrogation beam toward the excitation location of the sample; directing a signal enhancement beam to the sample, to raise a temperature of a portion of the sample by 5 Kelvin or less, compared to a temperature of the portion of the sample in absence of the signal enhancement beam; detecting a portion of the interrogation beam returning from the sample that is indicative of the generated signals.

Abstract: A method for visualizing details in a sample including directing an excitation beam to an excitation location below a surface of the sample, to generate signals in the sample; directing an interrogation beam toward the excitation location of the sample; directing a signal enhancement beam to the sample, to raise a temperature of a portion of the sample by 5 Kelvin or less, compared to a temperature of the portion of the sample in absence of the signal enhancement beam; detecting a portion of the interrogation beam returning from the sample that is indicative of the generated signals.

Abstract: A photoacoustic remote sensing system for imaging a subsurface structure in a sample, comprising exactly one laser source configured to generate a pulsed or intensity-modulated excitation beam configured to generate ultrasonic pressure signals in the sample at an excitation location, and an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic pressure signals, an optical system configured to focus the excitation beam and the interrogation beam below a surface of the sample, a detector configured to detect the returning portion of the interrogation beam, and a processor configured to calculate an image of the sample based on a detected intensity modulation of the returning portion of the interrogation beam from below the surface of the sample.

Abstract: A photoacoustic remote sensing system (NI-PARS) for imaging a subsurface structure in a sample, has an excitation beam configured to generate ultrasonic signals in the sample at an excitation location; an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals; an optical system that focuses at least one of the excitation beam and the interrogation beam with a focal point that is below the surface of the sample; and a detector that detects the returning portion of the interrogation beam.

Abstract: A photoacoustic remote sensing system for imaging a subsurface structure in a sample, comprising exactly one laser source configured to generate a pulsed or intensity-modulated excitation beam configured to generate ultrasonic pressure signals in the sample at an excitation location, and an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic pressure signals, an optical system configured to focus the excitation beam and the interrogation beam below a surface of the sample, a detector configured to detect the returning portion of the interrogation beam, and a processor configured to calculate an image of the sample based on a detected intensity modulation of the returning portion of the interrogation beam from below the surface of the sample.

Abstract: A photoacoustic remote sensing system (NI-PARS) for imaging a subsurface structure in a sample, has an excitation beam configured to generate ultrasonic signals in the sample at an excitation location; an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals; an optical system that focuses at least one of the excitation beam and the interrogation beam with a focal point that is below the surface of the sample; and a detector that detects the returning portion of the interrogation beam.

Abstract: A photoacoustic remote sensing system (PARS) for imaging a subsurface structure in a sample has an excitation beam configured to generate ultrasonic signals in the sample at an excitation location; an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals; an optical system that focuses at least one of the excitation beam and the interrogation beam with a focal point that is below the surface of the sample; and a detector that detects the returning portion of the interrogation beam.

Abstract: A photoacoustic remote sensing system (PARS) for imaging a subsurface structure in a sample has an excitation beam configured to generate ultrasonic signals in the sample at an excitation location; an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals; an optical system that focuses at least one of the excitation beam and the interrogation beam with a focal point that is below the surface of the sample; and a detector that detects the returning portion of the interrogation beam.

Abstract: A method for visualizing details in a sample including directing an excitation beam to an excitation location below a surface of the sample, to generate signals in the sample; directing an interrogation beam toward the excitation location of the sample; directing a signal enhancement beam to the sample, to raise a temperature of a portion of the sample by 5 Kelvin or less, compared to a temperature of the portion of the sample in absence of the signal enhancement beam; detecting a portion of the interrogation beam returning from the sample that is indicative of the generated signals.

Abstract: A photoacoustic remote sensing system (PARS) for imaging a subsurface structure in a sample, comprising one or more laser sources configured to generate a plurality of excitation beams configured to generate pressure signals in the sample at an excitation location, and a plurality of interrogation beams incident on the sample at the excitation location, a portion of the plurality of interrogation beams returning from the sample that is indicative of the generated pressure signals, an optical system configured to focus the plurality of excitation beams at a first focal point and the plurality of interrogation beams at a second focal point, the first and second focal points being below the surface of the sample, and a plurality of detectors each configured to detect a returning portion of at least one of the plurality of interrogation beams.

Abstract: A photoacoustic remote sensing system for imaging a subsurface structure in a sample, comprising exactly one laser source configured to generate a pulsed or intensity-modulated excitation beam configured to generate ultrasonic pressure signals in the sample at an excitation location, and an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic pressure signals, an optical system configured to focus the excitation beam and the interrogation beam below a surface of the sample, a detector configured to detect the returning portion of the interrogation beam, and a processor configured to calculate an image of the sample based on a detected intensity modulation of the returning portion of the interrogation beam from below the surface of the sample.

Abstract: A camera-based photoacoustic remote sensing system (C-PARS) for imaging a subsurface and deep structures in a sample, has an excitation beam configured to generate ultrasonic signals in the sample at an excitation location; an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals; a camera to map the returning portion of the interrogation beam over the entire field of view.

Abstract: A photoacoustic remote sensing system (NI-PARS) for imaging a subsurface structure in a sample, has an excitation beam configured to generate ultrasonic signals in the sample at an excitation location; an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals; an optical system that focuses at least one of the excitation beam and the interrogation beam with a focal point that is below the surface of the sample; and a detector that detects the returning portion of the interrogation beam.

Abstract: A coherence gated photoacoustic remote sensing system for imaging a subsurface structure in a sample with optical resolution may include an excitation beam source configured to generate an excitation beam that induces ultrasonic signals in the sample at an excitation location; an interrogation team source configured to generate an interrogation team incident on the sample at an interrogation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals, the interrogation beam being a low-coherent beam; an optical system that focuses the excitation beam onto the sample at an excitation location, and focuses the interrogation beam onto the sample at an interrogation location, at least the interrogation location being below the surface of and within the sample; and a low coherence interferometer that isolates a returning portion of the interrogation beam that corresponds to an interrogation event of the sample.

Abstract: A photoacoustic remote sensing system (PARS) for imaging a subsurface structure in a sample has an excitation beam configured to generate ultrasonic signals in the sample at an excitation location; an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals; an optical system that focuses at least one of the excitation beam and the interrogation beam with a focal point that is below the surface of the sample; and a detector that detects the returning portion of the interrogation beam.

Abstract: A camera-based photoacoustic remote sensing system (C-PARS) for imaging a subsurface and deep structures in a sample, has an excitation beam configured to generate ultrasonic signals in the sample at an excitation location; an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals; a camera to map the returning portion of the interrogation beam over the entire field of view.

Abstract: A photoacoustic remote sensing system (PARS) for imaging a subsurface structure in a sample has an excitation beam configured to generate ultrasonic signals in the sample at an excitation location; an interrogation beam incident on the sample at the excitation location, a portion of the interrogation beam returning from the sample that is indicative of the generated ultrasonic signals; an optical system that focuses at least one of the excitation beam and the interrogation beam with a focal point that is below the surface of the sample; and a detector that detects the returning portion of the interrogation beam.