Various aspects are directed to systems and methods for assessing neural activity of a neural region having multiple subfields. In certain embodiments, a method includes evoking a cellular electrical response in at least one subfield due to neural activity in the neural region, capturing image data of the electrical response at a level sufficiently detailed in space and time to differentiate between polarization-based events of two respective portions of the subfield, and then assessing neural activity by correlating space and time information, from the captured data, for the two respective portions of the sub-field. Other more specific aspects of the invention involve different preparation and neural stimulation approaches which can vary depending on the application.

Various aspects are directed to systems and methods for assessing neural activity of a neural region having multiple subfields. In certain embodiments, a method includes evoking a cellular electrical response in at least one subfield due to neural activity in the neural region, capturing image data of the electrical response at a level sufficiently detailed in space and time to differentiate between polarization-based events of two respective portions of the subfield, and then assessing neural activity by correlating space and time information, from the captured data, for the two respective portions of the sub-field. Other more specific aspects of the invention involve different preparation and neural stimulation approaches which can vary depending on the application.

Probe beams are scanned with respect to waveguide substrates to generate optical harmonics. Detection of the optical harmonic radiation is used to image waveguide cores, claddings, or other structures such as electrodes. The detected optical radiation can also be used to provide estimates of linear electrooptic coefficients, or ratios of linear electrooptic coefficients. In some cases, the poling of polymer waveguide structures is monitored during fabrication based on a second harmonic of the probe beam. In some examples, third harmonic generation is used for imaging of conductive layers.

An optical inspection device for an optical performance test of a display device including a lens part configured to transmit external light, a phase film part configured to change a phase difference of the external light and transmit the external light, and an image processor configured to obtain electrical information of the external light, in which a phase difference of the phase film part is at least 7000 nm.