Systems and methods for bond-selective transient phase imaging

A method for generating a bond-selective transient phase (BTSP) image of a sample, the method comprising:

• directing, using a probe laser source, a first plurality of probe laser pulses through the sample and an objective lens;
• dividing, using a transmission grate and one or more lenses, each of the first plurality of probe laser pulses into a plurality of waves to generate a first interferogram at an image plane of a camera;
• generating, using the camera, first image data reproducible as a first phase image of the sample based at least in part on the first interferogram;
• directing, using (i) a pump laser, (ii) a chopper, (iii) a shutter, and (iv) a plurality of mirrors, a plurality of laser bursts onto the sample to heat at least a portion of the sample, each of the plurality of pump laser bursts having a first wavelength and including at least one pump laser pulse;
• directing, using the probe laser source, a second plurality of probe laser pulses through the sample and the objective lens, each of the second plurality of probe laser pulses passing through the sample at a predetermined time delay subsequent to a corresponding one of the plurality of pump laser bursts;
• dividing the each of the second plurality of probe laser pulses into a plurality of waves to generate a second interferogram at the image plane of the camera;
• generating, using the camera, second image data reproducible as a second phase image of the sample based at least in part on the second interferogram;
• and
• generating a bond-selective transient phase (BTSP) image of the sample based at least in part on the first phase image and the second phase image.

A system for generating a bond-selective transient phase (BSTP) image of a sample, the system comprising:

• a probe laser configured to emit a probe laser beam;
• a pump laser configured to emit a pump laser beam;
• a chopper positioned between the pump laser and the sample;
• a shutter positioned between the chopper and the sample, the shutter including an aperture;
• a camera;
• an objective lens positioned between the sample and the camera;
• a memory storing machine-readable instructions;
• and
• a control system including one or more processors, the control system configured to execute the machine-readable instructions to:
• cause the probe laser to generate a first plurality of probe laser pulses such that the first plurality of probe laser pulses are directed through the sample and the objective lens to form a first interferogram at an image plane of the camera;
• cause the camera to generate first image data reproducible as a first phase image of the sample based at least in part on the first interferogram;
• cause the chopper to modulate the pump laser beam to generate a plurality of pump laser bursts, each of plurality of pump laser bursts (i) having a first wavelength and (ii) including at least one pump laser pulse;
• cause the shutter to move from a first position to a second position to permit the plurality of pump laser bursts to pass through the aperture for a predetermined duration such that the plurality of pump laser bursts heat at least a portion of the sample;
• cause the probe laser to generate a second plurality of probe laser pulses from the probe laser beam such that (i) each of the second plurality of probe laser pulses are directed through the sample at a predetermined time delay subsequent to a corresponding one of the plurality of pump laser bursts and (ii) the second plurality of probe laser pulses form a second interferogram at the image plane of the camera;
• cause the camera to generate second image data reproducible as a second phase image of the sample based at least in part on the second interferogram;
• and
• generate a bond-selective transient phase (B STP) image of the sample based at least in part on the first phase image and the second phase image.