Abstract: A monolithic, side pumped, passively Q-switched, solid-state laser (10) includes a laser resonator structure (16) that includes a laser gain medium (12) having an output face bonded to a passive Q-switch (14). The gain medium (12) has a side face (12A) for receiving pump light. The pump light is preferably generated by a laser diode array (20). In a further embodiment, a non-linear optical material (22), such as frequency doubling KTP, is optically coupled to an output face of the Q-switch for providing output wavelength conversion. A method is also disclosed for fabricating the monolithic, side pumped, passively Q-switched, solid-state laser. Techniques are included for providing compensation from thermal aberrations during operation of the laser.

Abstract: A method and an apparatus are disclosed for limiting the readability of optically-readable medium, wherein a combination of a liquid crystal material and a wavelength shifting material are incorporated into the optically-readable medium. The liquid crystal material is selected to substantially interfere with the reading beam of a reading device. The wavelength shifting material is selected to shift the wavelength at which the liquid crystal interferes with the reading beam so that the reading beam can read the optically-readable medium. A predetermined stimulus causes the liquid crystal material to shift back to a configuration that substantially interferes with the reading beam so that the reading beam can no longer read the content on the optically readable medium.

Abstract: A solid state Raman laser includes a laser pump for producing a first radiation at a high power and at a first wavelength along an optical path, a solid Raman active medium in the optical path of the first radiation, the medium including single crystal diamond having a first surface and a second surface, where the first radiation at a high power produces stimulated Raman scattering in the medium and the medium generates a second radiation at a second wavelength, a first optical element in the optical path of the first radiation, wherein the first optical element allows the first wavelength to be transmitted and allows the second wavelength to be reflected, and a second optical element in the optical path of the first radiation, wherein the second optical element allows the first wavelength to be transmitted and allows the second wavelength to be reflected.

Abstract: Disclosed herein are methods and apparatus for authentication of various substrates, including paper based substrates such as currency. Techniques are disclosed for use of security features to generate security codes. The security codes are deciphered with apparatus including a color recognition sub-system that provides for verification of authenticity of the substrate containing the security features.

Abstract: Disclosed herein is a system for recording a marking in the readout area of an optical media, wherein the marking does not interfere, or substantially interfere, with the readout of data from the optical media. The system disclosed herein is supportive of commercial production requirements. Markings may contain content as desired by the user of the system, including text, graphics, or other items. The marking is formed in a photosensitive coating that is applied to the optical media, and then cured with a first light. A second light, having a substantially separate band of wavelengths from the first light, is used to image a marking into the coating. The coating is robust to many external influences, such as ambient environmental conditions, and physical wear.