摘要:
In one aspect of the present invention, a device for sensing an absolute position of an encoded object, comprising: a position tracking module comprising: a track illumination module configured to illuminate the encoded object with one more light beams, and to detect one or more light beams resulting from said illumination of said encoded object; and an absolute position determinator configured to determine the absolute position of the encoded object based on said one or more light beams resulting from said illumination of said encoded object.
摘要:
Systems and methods are provided or use with a light source which generates a light beam. These systems may include a detector which detects light beam information and which determines whether multiple modes are present in the light beam so that the light source may be adjusted. These systems may further include a beam splitting device, such as an optical wedge, to provide two sample beams that intersect to provide a fringe pattern. The detector may then detect this fringe pattern and compute a visibility value that may be used to determine whether multiple modes are present.
摘要:
The present invention relates to embodiments of a process for subjecting a holographic storage medium to illuminative treatment to: (1) enhance or optimize recording of holographic data; (2) enhance or optimize reading of recorded holographic data; and/or (3) erase recorded holographic data. The present invention also relates to embodiments of a system comprising: (a) an illuminative treatment beam; (b) means for reducing the coherence of the beam and (c) means for transmitting the reduced coherence beam to cause illuminative treatment of: (1) an unrecorded portion of a holographic storage medium to provide pre-cured portions having increased ability to stably record holographic data; (2) a recorded portion of a holographic storage medium to provide a post-cured portion having reduced residual sensitivity; and/or (3) a recorded portion of a holographic storage medium having holographic data to provide an erased portion wherein at least some of the recorded holographic data is erased.
摘要:
A wavelength router is provided that selectively directs spectral bands between an input port and a set of output ports. The router includes a free-space optical train disposed between the input port and the output ports. The free-space optical train may include air-spaced elements or may be of generally monolithic construction. The optical train includes a transmissive dispersive element, such as a transmissive diffraction grating, disposed so that light is intercepted from the input port and encounters the transmissive dispersive element at least four times before reaching any of the output ports.
摘要:
A diffraction grating is fabricated by forming two sets of parallel trenches in a crystal surface, one set with a crystalline-independent etching technique and the other made with a chemically crystalline-dependent etchant. The intersection of the two sets of trenches removes material from the crystal surface to produce an etched crystal surface that can be coated with a reflective material to form the diffraction grating or can be used as a master for batch fabrication of diffraction gratings.
摘要:
The present invention relates to embodiments of a process for subjecting a holographic storage medium to illuminative treatment to: (1) enhance or optimize recording of holographic data; (2) enhance or optimize reading of recorded holographic data; and/or (3) erase recorded holographic data. The present invention also relates to embodiments of a system comprising: (a) an illuminative treatment beam; (b) means for reducing the coherence of the beam and (c) means for transmitting the reduced coherence beam to cause illuminative treatment of: (1) an unrecorded portion of a holographic storage medium to provide pre-cured portions having increased ability to stably record holographic data; (2) a recorded portion of a holographic storage medium to provide a post-cured portion having reduced residual sensitivity; and/or (3) a recorded portion of a holographic storage medium having holographic data to provide an erased portion wherein at least some of the recorded holographic data is erased.
摘要:
A diffraction grating that achieves high diffraction efficiency at all polarizations for optical signals at telecommunications wavelengths is provided. The diffraction grating has a substrate and a plurality of reflective faces oriented at respective blaze angles θb spaced along the substrate surface, with the blaze angles substantially differ from the Lit trow condition. Each reflective surface is supported by a support wall connected substantially with the substrate surface.
摘要:
A reflective lamellar diffraction grating is provided that is suitable for a variety of applications, including applications related to C-band telecommunication functions. The average efficiency of the diffraction grating in S- and P-polarization states exceeds 90% while simultaneously providing a PDL less than 0.2 dB over the entire wavelength range used for C-band telecommunication functions. The diffraction grating is thus suitable for incorporation into various telecommunication systems, including a wavelength router configured for routing signals having a plurality of spectral bands.
摘要:
A diffraction grating that achieves high diffraction efficiency at all polarizations for optical signals at telecommunications wavelengths is provided. The diffraction grating has a substrate and a plurality of reflective faces oriented at respective blaze angles &thgr;b spaced along the substrate surface, with the blaze angles substantially differ from the Littrow condition. Each reflective surface is supported by a support wall connected substantially with the substrate surface.
摘要:
The present invention relates to a system comprising a holographic data storage drive that records holographic digital data in a holographic recording medium, and which comprises: a data beam path having a first optical path length; and a reference beam path having a second optical path length; wherein one of the data beam and reference beams paths comprise an optical delay line so that the difference between the first and second optical path lengths is less than the laser coherence length. The present invention further relates to a method for operating a laser in the holographic data storage drive in a multi-mode state during the recording of holographic digital data the holographic medium without adverse effects on the strength of the interference patterns formed.