A device for manufacturing a replica hologram, comprising a holder for a light-sensitive recording material, into which the replica hologram is to be imprinted, a holder for a master hologram, as well as a lighting device for generating light for exposing the master hologram, the color of the light generated by the lighting device being variable, and the lighting device comprising optics for exposing the master hologram with the aid of the light generated by the lighting device, the device being designed in such a way that the light emanating from the master hologram impinges on the recording material to manufacture the replica hologram.

A light source device connected to an optical fiber and emit light from the optical fiber, the device includes: a plurality of laser light sources to respectively emit light at different wavelengths; a current source to supply a drive current with a superimposed alternating-current component to each laser light source; a light source control section to selectively switch the laser light sources by controlling the current sources; a plurality of optical systems disposed in optical paths of the respective laser light sources to reflect the light from the respective laser light sources to an incident end of the optical fiber and to reflect return light reflected on the incident end to the respective laser light sources; and a return light adjustment section to adjust an amount of the return light to continuously spread a spectrum of the light emitted from the optical fiber.

A projection system that facilitates the use of in-situ detection of a change in wavelength, thereby enabling appropriate compensation or corrections to be applied on the fly to improve the quality of the image in the primary image region. In-situ detection in this manner can allow wavelength changes due to both temperature fluctuations and hardware variations to be compensated for simultaneously, thereby reducing the time and expense for end of line hardware testing, and removing the need to perform in-situ mapping of the wavelength as a function of temperature. In this way, the quality of the image provided to a user can be improved in a simpler, more efficient manner.

A dark field digital holographic microscope and associated metrology method is disclosed which is configured to determine a characteristic of interest of a structure. The dark field digital holographic microscope includes an illumination branch for providing illumination radiation to illuminate the structure; a detection arrangement for capturing object radiation resulting from diffraction of the illumination radiation by the structure; and a reference branch for providing reference radiation for interfering with the object radiation to obtain an image of an interference pattern formed by the illumination radiation and reference radiation. The reference branch has an optical element operable to vary a characteristic of the reference radiation so as to reduce and/or minimize variation in a contrast metric of the image within a field of view of the dark field digital holographic microscope at a detector plane.

The invention discloses a digital laser holography-based rapid lens center offset detection device, which relates to the technical field of lens detection and includes a spherical wave emission device, a reticle, a lens to be detected, an image sensor and a computer. The device is simple and stable in structure, and a complex optical receiving system and mechanical scanning are avoided. A detection method is high in efficiency and measurement accuracy, a process is simple, and a lens with an infinitely great focal length may be detected.

The invention discloses a digital laser holography-based rapid lens center offset detection device, which relates to the technical field of lens detection and includes a spherical wave emission device, a reticle, a lens to be detected, an image sensor and a computer. The device is simple and stable in structure, and a complex optical receiving system and mechanical scanning are avoided. A detection method is high in efficiency and measurement accuracy, a process is simple, and a lens with an infinitely great focal length may be detected.

A light source device connected to an optical fiber and emit light from the optical fiber, the device includes: a plurality of laser light sources to respectively emit light at different wavelengths; a current source to supply a drive current with a superimposed alternating-current component to each laser light source; a light source control section to selectively switch the laser light sources by controlling the current sources; a plurality of optical systems disposed in optical paths of the respective laser light sources to reflect the light from the respective laser light sources to an incident end of the optical fiber and to reflect return light reflected on the incident end to the respective laser light sources; and a return light adjustment section to adjust an amount of the return light to continuously spread a spectrum of the light emitted from the optical fiber.

A projection system that facilitates the use of in-situ detection of a change in wavelength, thereby enabling appropriate compensation or corrections to be applied on the fly to improve the quality of the image in the primary image region. In-situ detection in this manner can allow wavelength changes due to both temperature fluctuations and hardware variations to be compensated for simultaneously, thereby reducing the time and expense for end of line hardware testing, and removing the need to perform in-situ mapping of the wavelength as a function of temperature. In this way, the quality of the image provided to a user can be improved in a simpler, more efficient manner.

A method for irradiating a medium includes irradiating the medium with an electromagnetic wave which is scattered in the medium and modulated in frequency at a position in the medium; obtaining information corresponding to an interference pattern generated by interference between the modulated electromagnetic wave and a reference wave; and generating a phase conjugate wave, based on the obtained information, which irradiates the medium.

A projection system that facilitates the use of in-situ detection of a change in wavelength, thereby enabling appropriate compensation or corrections to be applied on the fly to improve the quality of the image in the primary image region. In-situ detection in this manner can allow wavelength changes due to both temperature fluctuations and hardware variations to be compensated for simultaneously, thereby reducing the time and expense for end of line hardware testing, and removing the need to perform in-situ mapping of the wavelength as a function of temperature. In this way, the quality of the image provided to a user can be improved in a simpler, more efficient manner.