Abstract: Apparatus include a photoelastic modulator (PEM) optical element, a controller having a frequency generator configured to produce a frequency signal at a selected frequency based on a clock signal of the controller wherein the controller is configured to produce a PEM driving signal based on the frequency signal, a PEM transducer coupled to the PEM optical element and the controller and configured to drive the PEM with the PEM driving signal, and a detector optically coupled to the PEM optical element and configured to receive a PEM modulated output and to produce a PEM detection signal that includes a PEM modulation signal, wherein the controller is configured to receive the PEM detection signal and to extract the PEM modulation signal from the PEM detection signal using the frequency signal and the clock signal.

Abstract: An apparatus includes an elastically deformable optical element holder situated to receive an optical element having a plurality of holder contact surfaces, the optical element holder including a plurality of receiving portions adjacent to an aperture and corresponding to respective holder contact surfaces, each receiving portion displaceable through deformation of the optical element holder so that the optical element is insertable in the aperture so as to be cushionably supported in a predetermined position with the receiving portions in contact with the respective holder contact surfaces.

Abstract: An apparatus includes a photoelastic modulator (PEM) optical element including a first driving axis and a second driving axis arranged at a selected angle with respect to each other and perpendicular to an optical axis, wherein the first driving axis and the second driving axis extend respective predetermined non-equal lengths that correspond to respective predetermined non-equal natural first and second PEM frequencies f1 and f2. Methods of manufacture and operation are also disclosed.

Abstract: Apparatus include a photoelastic modulator (PEM) optical element, a controller having a frequency generator configured to produce a frequency signal at a selected frequency based on a clock signal of the controller wherein the controller is configured to produce a PEM driving signal based on the frequency signal, a PEM transducer coupled to the PEM optical element and the controller and configured to drive the PEM with the PEM driving signal, and a detector optically coupled to the PEM optical element and configured to receive a PEM modulated output and to produce a PEM detection signal that includes a PEM modulation signal, wherein the controller is configured to receive the PEM detection signal and to extract the PEM modulation signal from the PEM detection signal using the frequency signal and the clock signal.

Abstract: An apparatus includes a photoelastic modulator (PEM) optical element including a first driving axis and a second driving axis arranged at a selected angle with respect to each other and perpendicular to an optical axis, wherein the first driving axis and the second driving axis extend respective predetermined non-equal lengths that correspond to respective predetermined non-equal natural first and second PEM frequencies f1 and f2. Methods of manufacture and operation are also disclosed.

Abstract: Example embodiments of methods, apparatus, and systems for measuring polarimetric parameters using spectroscopy are disclosed herein. Particular embodiments concern circular dichroism (CD) spectrometers that use a vertically aligned beam. In such embodiments, the solution being analyzed may have a top surface that forms a convex or concave meniscus, creating a surface through which the measuring beam passes that may refract the beam in undesirable ways. Accordingly, particular embodiments of the disclosed technology include one or more meniscus-compensating (meniscus-effect-reducing) components or subsystems. These components and/or subsystems can be used alone or in combination with one another to reduce the undesirable refractive effects caused by the meniscus at the solution's surface, thereby improving the resulting quality of the spectroscopy measurement and potentially improving the speed with which CD spectroscopy can be performed.

Abstract: An apparatus includes an elastically deformable optical element holder situated to receive an optical element having a plurality of holder contact surfaces, the optical element holder including a plurality of receiving portions adjacent to an aperture and corresponding to respective holder contact surfaces, each receiving portion displaceable through deformation of the optical element holder so that the optical element is insertable in the aperture so as to be cushionably supported in a predetermined position with the receiving portions in contact with the respective holder contact surfaces.

Abstract: This invention is directed to methods of unambiguously measuring the absolute retardance, ?A of an optical sample. A method for measuring absolute retardance of an optical sample includes directing light comprising a plurality of wavelengths through a polarization state generator source, the optical sample, and a polarization state analyzer, detecting, at an imaging device, retardance measurement light emanating from the optical sample after also passing through the polarization state analyzer at the plurality of wavelengths, determining a measurement retardance associated with the detected retardance measurement light at each of the wavelengths, and determining an absolute retardance associated with the optical sample based on the measurement retardances determined at each of the wavelengths.

Abstract: This disclosure is generally directed to systems for imaging polarization properties of optical-material samples. As one aspect, there is provided a system for precise, simultaneous imaging of both the in-plane and out-of-plane birefringence properties of sample material over a wide range of incidence angles. The spatially resolved imaging approach described here is amenable to determination of a wide range of polarimetric properties, in addition to the in-plane and out-of-plane birefringence measure discussed as a preferred embodiment.

Abstract: This disclosure is generally directed to systems for imaging polarization properties of optical-material samples. As one example, there is provided a system for precise, simultaneous imaging of both the in-plane and out-of-plane birefringence properties of sample material over a wide range of incidence angles. An example spatially resolved imaging approach described herein is amenable to determination of a wide range of polarimetric properties, in addition to the in-plane and out-of-plane birefringence measure discussed as a preferred embodiment.

Abstract: This disclosure is generally directed to systems for imaging polarization properties of optical-material samples. As one example, there is provided a system for precise, simultaneous imaging of both the in-plane and out-of-plane birefringence properties of sample material over a wide range of incidence angles. An example spatially resolved imaging approach described herein is amenable to determination of a wide range of polarimetric properties, in addition to the in-plane and out-of-plane birefringence measure discussed as a preferred embodiment.

Abstract: This invention is directed to methods of unambiguously measuring the absolute retardance, ?A of an optical sample. A method for measuring absolute retardance of an optical sample includes directing light comprising a plurality of wavelengths through a polarization state generator source, the optical sample, and a polarization state analyzer, detecting, at an imaging device, retardance measurement light emanating from the optical sample after also passing through the polarization state analyzer at the plurality of wavelengths, determining a measurement retardance associated with the detected retardance measurement light at each of the wavelengths, and determining an absolute retardance associated with the optical sample based on the measurement retardances determined at each of the wavelengths.

Abstract: A birefringence measurement system includes a lens mounted for selective movement into and out of use in the optical setup so that a wide range of sample types can be handled by the system without reconfiguring the primary components of the optical setup of the system (moving the detector, changing the light source power, etc.) in a manner that would sacrifice the cost effectiveness, efficiency, mechanical reliability and repeatability of measurements for such systems.

Abstract: A birefringence measurement system includes a lens mounted for selective movement into and out of use in the optical setup so that a wide range of sample types can be handled by the system without reconfiguring the primary components of the optical setup of the system (moving the detector, changing the light source power, etc.) in a manner that would sacrifice the cost effectiveness, efficiency, mechanical reliability and repeatability of measurements for such systems.

Abstract: A system for measuring linear or circular diattenuation in an optical element includes a sample rotation stage for securing an optical element sample; a light source module for generating a source light beam and a detector module. The light source module and detector module are arranged with the sample rotation stage between them, thereby permitting the source light beam to propagate through a sample that may be secured in the sample stage and to the detector module. Linear motion control of the light source module and the detector module, as well as tilt control of the light source module, the sample rotation stage and the detector module is provided, thereby to facilitate detection, by the detector module of the modulated light intensity information corresponding to a diattenuation characteristic of the optical sample secured in the sample stage.

Abstract: A mechanism and method for precisely arranging two or more optical elements, such as those incorporated into photoelastic modulators (PEMs), at a specific angular orientation. The method includes supporting one optical element in an annular mounting member that has an optic axis, and supporting other optical elements in other annular mounting members that have optic axes, and concentrically stacking together the two or more mounting members about a central axis in a manner such that one mounting member may be rotated relative to the others about the central axis and such that the optic axes of the mounting members define an optics angle, and rotating one mounting member relative to the others to define the specific angular orientation of the optical elements.

Abstract: A mechanism and method for precisely arranging two or more optical elements, such as those incorporated into photoelastic modulators (PEMs), at a specific angular orientation. The method includes supporting one optical element in an annular mounting member that has an optic axis, and supporting other optical elements in other annular mounting members that have optic axes, and concentrically stacking together the two or more mounting members about a central axis in a manner such that one mounting member may be rotated relative to the others about the central axis and such that the optic axes of the mounting members define an optics angle, and rotating one mounting member relative to the others to define the specific angular orientation of the optical elements.

Abstract: A method of controlling a light beam in an optical system includes a light source that directs a collimated light beam along a path, through a sample, and toward the active area of a stationary detector. The method includes the step selectively moving a lens into the path of the light beam for spreading the beam in instances where the path of the beam is altered by the sample between the source and the stationary detector. The detector, therefore, is held stationary. Adjustment means are provided for increasing the intensity characteristic of the light that reaches the detector to account for a decrease in intensity that occurs when the lens is in the path of the light beam to spread the beam.

Abstract: A method of controlling a light beam in an optical system includes a light source that directs a collimated light beam along a path, through a sample, and toward the active area of a stationary detector. The method includes the step selectively moving a lens into the path of the light beam for spreading the beam in instances where the path of the beam is altered by the sample between the source and the stationary detector. The detector, therefore, is held stationary. Adjustment means are provided for increasing the intensity characteristic of the light that reaches the detector to account for a decrease in intensity that occurs when the lens is in the path of the light beam to spread the beam.

Abstract: Improving the throughput of systems for measuring birefringence of optical samples includes techniques for directing multiple beams through the photoelastic modulator component of the system so that, along with expanded detection mechanisms to accommodate the multiple beams, the heretofore scanning (via a single beam) of a line across the sample is considerably enlarged so that several lines covering a “swath” of the sample area is scanned by the system of the present invention.