Method and system for measuring at least one property including a magnetic property of a material using pulsed laser sources

A method of measuring at least one property including a magnetic property of target material, the method comprising the steps of:

• generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material;
• generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probepulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation;
• electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses;
• detecting each modulated probe pulse to obtain one or more corresponding signals;
• and
• processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material, wherein the at least one property also includes a thermal property of the target material and wherein the method further comprises adjusting pump beam intensity to modify transient temperature and stress to allow correlation between the thermal and magnetic properties.

A method of measuring at least one property including a magnetic property of target material, the method comprising the steps of:

• generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material;
• generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation;
• electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses;
• detecting each modulated probe pulse to obtain one or more corresponding signals;
• and
• processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material, wherein the at least one property also includes a mechanical property of the target material and wherein the method further comprises adjusting pump beam intensity to select transient temperature and stress to allow correlation between the mechanical and magnetic properties.

A method of measuring at least one property including a magnetic property of target material, the method comprising the steps of:

• generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material;
• generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation;
• electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses;
• detecting each modulated probe pulse to obtain one or more corresponding signals;
• and
• processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material, and wherein the method further comprises adjusting pump beam intensity to determine thresholds for at least one of permanent material modification and change.

A method of measuring at least one property including a magnetic property of target material, the method comprising the steps of:

• generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material;
• generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation;
• electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses;
• detecting each modulated probe pulse to obtain one or more corresponding signals;
• and
• processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material, and wherein the method further comprises controlling polarization orientation of the pump and probe pulses to one of linear, circular or elliptical polarization for perturbation excitation and detection to measure component resolved magnetization dynamics or vector-resolved MOKE technique for characterization.

A method of measuring at least one property including a magnetic property of target material, the method comprising the steps of:

• generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least aportion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material;
• generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation;
• electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses;
• detecting each modulated probe pulse to obtain one or more corresponding signals;
• and
• processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material, and wherein the method further comprises adjusting relative phase and polarization between pairs of probe pulses.

A method of measuring at least one property including a magnetic property of target material, the method comprising the steps of:

• generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material;
• generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation;
• electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses;
• detecting each modulated probe pulse to obtain one or more corresponding signals;
• and
• processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material, and wherein the method further comprises increasing pump laser intensity to generate at least one of laser-induced large amplitude magnetic oscillations and transient magnetization switching to measure magnetization switching speed.

A method of measuring at least one property including a magnetic property of target material, the method comprising the steps of:

• generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material;
• generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation;
• electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses;
• detecting each modulated probe pulse to obtain one or more corresponding signals;
• and
• processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material, and wherein the method further comprises controlling intensity and relative timing of at least two pump or probe beam pair sequences for enhanced perturbation excitation and detection, respectively.

A method of measuring at least one property including a magnetic property of target material, the method comprising the steps of:

• generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material;
• generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation;
• electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses;
• detecting each modulated probe pulse to obtain one or more corresponding signals;
• and
• processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material, and wherein the method further comprises controlling relative polarization between pair of probe and pump pulses to select either a magnetic, a thermal or a mechanical characterization mode of the operation.

A method of measuring at least one property including a magnetic property of target material, the method comprising the steps of:

• generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material;
• generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation;
• electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses;
• detecting each modulated probe pulse to obtain one or more corresponding signals;
• and
• processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material, and wherein the method further comprises irradiating the target material with a CW beam during one of the steps of irradiating to either change temperature of the target material or to provide an additional ellipsometric probe.

A system for measuring at least one property including a magnetic property of target material, the system comprising:

• a pulsed laser source for generating a pump pulse train having one or more pump pulses at a repetition rate along a first propagation path, each pump pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• means for irradiating the target material with at least a portion of the one or more pump pulses focused into at least one spot having a spot shape and size so as to cause transient perturbation in the target material;
• a pulsed laser source for generating at least one probe pulse train having one or more probe pulses at a repetition rate along a second propagation path, each probe pulse having a pulse energy density, a laser wavelength within a range of laser wavelengths, and a pulse duration;
• means for irradiating the target material with at least a portion of the one or more probe pulses focused into at least one spot having a spot shape and size to obtain one or more reflected probe pulses which are modulated based on the transient perturbation;
• means for electronically controlling a time interval between a time at which the target material is irradiated by each of the focused pump pulses and a time at which the target material is irradiated by each of its corresponding focused probe pulses wherein the time interval is capable of being controlled to be greater than or less than 1 ns within a temporal measurement window from 10 fs to 500 ns;
• means for detecting each modulated probe pulse to obtain one or more corresponding signals;
• and
• means for processing the one or more signals to obtain one or more measurement signals which represents the at least one property including the magnetic property of the target material.