Field-biased nonlinear optical metrology using corona discharge source

A system for optically interrogating a surface of a sample accompanied by the application of electric charge to said sample, said system comprising:

• a first optical source configured to emit probing optical radiation, said first optical source disposed so as to direct said probing optical radiation onto said surface of said sample;
• a corona discharge source disposed with respect to the sample to provide different amounts of electric charge to the sample;
• an optical detector configured to detect second harmonic generated light from the sample;
• and
• electronics configured to determine a characteristic of the detected second harmonic generated light for the different amounts of the electrical charge.

A system for optically interrogating a surface of a sample accompanied by the application of electric charge to said sample, said system comprising:

• a first optical source configured to emit a first incident beam of light towards said surface of said sample;
• a second optical source configured to emit a second incident beam of light towards said surface of said sample;
• a corona discharge source disposed with respect to the sample to provide different amounts of electric charge to the sample;
• and
• an optical detection system configured to detect at least one four-wave mixing or at least one multi-wave mixing signal component from the sample for different amounts of electric charge on the sample;
• and
• electronics electrically connected to said optical detection system to receive a signal based on said detected at least one four-wave mixing or at least one multi-wave mixing signal component.

A method of optical interrogation of a sample having a top side and a bottom side, the method comprising:

• directing a first incident beam from a first optical source towards a region on a surface of the sample;
• directing a second incident beam from a second optical source towards the region on the surface of the sample;
• depositing different amounts of electrical charge on the top side of the sample using a corona gun;
• detecting using an optical detection system, at least one four-wave mixing signal component or at least one multi-wave mixing signal component from the sample generated by the first incident beam and the second incident beam for different amounts of electrical charge deposited on the top side of the sample.