A method includes: producing a light beam made up of pulses having a wavelength in the deep ultraviolet range, each pulse having a first temporal coherence defined by a first temporal coherence length and each pulse being defined by a pulse duration; for one or more pulses, modulating the optical phase over the pulse duration of the pulse to produce a modified pulse having a second temporal coherence defined by a second temporal coherence length that is less than the first temporal coherence length of the pulse; forming a light beam of pulses at least from the modified pulses; and directing the formed light beam of pulses toward a substrate within a lithography exposure apparatus.

Coherent spectroscopic methods are described, to measure the total phase difference during an extended interrogation interval between the signal delivered by a local oscillator (10) and that given by a quantum system (QS). According to one or more embodiments, the method may comprise reading out at the end of successive interrogation sub-intervals (Ti) intermediate error signals corresponding to the approximate phase difference (φ) between the phase of the LO signal and that of the quantum system, using coherence preserving measurements; shifting at the end of each interrogation sub-intervals (Ti) the phase of the local oscillator signal, by a known correction value (.sub.φ(i).sub.FB) so as to avoid that the phase difference approaches the limit of the inversion region; reading out a final phase difference (φf) between the phase of the prestabilized oscillator signal and that of the quantum system using a precise measurement with no restriction on the destruction; reconstructing a total phase difference over the extended interrogation interval, as the sum of the final phase difference (φf) and the opposite of all the applied phase corrections figure (I).

A device for modulating the phase of a light beam includes a matrix of elementary cells, called pixels, coupled to a circuit for addressing the pixels, the device further comprising a set of so-called lateral electrodes extending in a so-called vertical direction (Y) at right angles to the alignment direction (Xa) and configured to apply, for each pixel and via at least two lateral electrodes, a so-called acceleration voltage generating a lateral electrical field (Era) substantially parallel to the alignment direction, in a vector allowing an accelerated return of the liquid crystal molecules to their orientation of rest, the acceleration voltage being configured to be applied in a phase called acceleration relaxation phase, when the activation voltage is no longer applied.

A device for modulating the phase of a light beam includes a matrix of elementary cells, called pixels, coupled to a circuit for addressing the pixels, the device further comprising a set of so-called lateral electrodes extending in a so-called vertical direction (Y) at right angles to the alignment direction (Xa) and configured to apply, for each pixel and via at least two lateral electrodes, a so-called acceleration voltage generating a lateral electrical field (Era) substantially parallel to the alignment direction, in a vector allowing an accelerated return of the liquid crystal molecules to their orientation of rest, the acceleration voltage being configured to be applied in a phase called acceleration relaxation phase, when the activation voltage is no longer applied.

Conformal imaging vibrometer using adaptive optics with scene-based wave front sensing. An extended object is located at the first end of a link, and a reference-free, adaptive optical, conformal imaging vibrometer using scene-based wave front sensing is located at the second end of the link. An aberrated, free space or guided-wave path exists between the ends of the link. The adaptive optical system compensates for path distortions. Using a single interrogation beam, whole-body vibrations of opaque and reflective objects can be probed, as well as transparent and translucent objects, the latter pair employing a Zernike heterodyne interferometer.

Conformal imaging vibrometer using adaptive optics with scene-based wave front sensing. An extended object is located at the first end of a link, and a reference-free, adaptive optical, conformal imaging vibrometer using scene-based wave front sensing is located at the second end of the link. An aberrated, free space or guided-wave path exists between the ends of the link. The adaptive optical system compensates for path distortions. Using a single interrogation beam, whole-body vibrations of opaque and reflective objects can be probed, as well as transparent and translucent objects, the latter pair employing a Zernike heterodyne interferometer.

Embodiments are disclosed relating to a refractively-scanning interferometer comprising an aperture that receives an incident light beam at a receiving angle, a beam splitter configured to split the incident light beam into a first beam and a second beam, a first and a second reflector arranged to reflect the first beam and second beam, respectively, towards a combining optical element, and a refractive Optical Path Difference (rOPD) assembly interposed between the beam splitter and the first reflector, wherein the rOPD Assembly refracts the first light beam an even number of times with induced phase discrepancy being a vector sum of a first phase discrepancy induced by a first refraction and a second phase discrepancy induced by a second refraction, the rOPD Assembly being configured such that the first phase discrepancy is substantially opposite in direction to the second phase discrepancy, a portion of the first and second phase discrepancies cancelling one another out to decrease magnitude of the phase discrepancy.

Embodiments are disclosed relating to a refractively-scanning interferometer comprising an aperture that receives an incident light beam at a receiving angle, a beam splitter configured to split the incident light beam into a first beam and a second beam, a first and a second reflector arranged to reflect the first beam and second beam, respectively, towards a combining optical element, and a refractive Optical Path Difference (rOPD) assembly interposed between the beam splitter and the first reflector, wherein the rOPD Assembly refracts the first light beam an even number of times with induced phase discrepancy being a vector sum of a first phase discrepancy induced by a first refraction and a second phase discrepancy induced by a second refraction, the rOPD Assembly being configured such that the first phase discrepancy is substantially opposite in direction to the second phase discrepancy, a portion of the first and second phase discrepancies cancelling one another out to decrease magnitude of the phase discrepancy.

Apparatus and method for detecting wavefront aberration of an objective lens, comprising a wavefront detection system, a planar mirror, and a planar mirror adjusting mechanism; the objective lens is placed between planar mirror and wavefront detection system; planar mirror is positioned at focal point of the objective lens. A test wavefront emitted by wavefront detection system passes through the objective lens, gets reflected by the planar mirror, and t passes through the objective lens again; the wavefront detection system receives and detects the test wavefront to derive a phase distribution thereof; an angle of the planar mirror tilts at is adjusted to obtain different return wavefronts; a polynomial for expressing wavefront aberration is selected, and expressions corresponding to all the return wavefronts are calculated; result of fitting the wavefront aberration of the objective lens when expressed by the selected polynomial is derived through fitting with the polynomial.

A differential polarization interferometer is provided. An interferometer performs direct measurement of phase shift of a light wave passed under an arbitrary angle through a sample composed of a transparent substrate holding a thin deposited test film, for metamaterial testing. An example apparatus has a laser source and a first polarizer, and two optically connected arms. A first arm creates orthogonally polarized components of a single output beam for a broadband non-polarizing beam splitter. A second arm has a controllable phase retarder to introduce a phase shift into one polarization component of the reflected single output beam, and a second polarizer to equalize and mix the polarization components of the reflected single output beam. This transforms the reflected single output beam into a beam resulting from interference of polarization components of the reflected single output beam. A photodetector transforms an intensity of the beam into an electric signal for output.