Abstract: This application is applicable to the field of communications technologies, and provides an embedded subscriber identity module (eSIM) card identification method and a terminal device method. The method includes: after completing an initialization process, driving an eSIM card to be powered on; querying whether an activated profile exists in the eSIM card; and when a query result is that no activated profile exists in the eSIM card, powering off the eSIM card. When the eSIM card is not activated or no activated profile exists in the eSIM card, it indicates that a user does not need to use a related function or service of the eSIM card. In this case, the eSIM card is powered off. When the eSIM card is not activated, it means that no profile exists in the eSIM card.

Abstract: This application is applicable to the field of communications technologies, and provides an embedded subscriber identity module (eSIM) card identification method and a terminal device method. The method includes: after completing an initialization process, driving an eSIM card to be powered on; querying whether an activated profile exists in the eSIM card; and when a query result is that no activated profile exists in the eSIM card, powering off the eSIM card. When the eSIM card is not activated or no activated profile exists in the eSIM card, it indicates that a user does not need to use a related function or service of the eSIM card. In this case, the eSIM card is powered off. When the eSIM card is not activated, it means that no profile exists in the eSIM card.

Abstract: A method of minimizing contamination of optical components of a laser resonator is disclosed. The resonator components are located in an enclosure, which may contain contaminants including water vapor and organic favor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a desiccant, an organic vapor trapping material, and a particulate matter filter then returns the extracted gas to the enclosure. The purging system is particularly useful for ultrafast lasers and ultraviolet lasers where the power of the laser radiation increases the probability of destabilizing reactions between laser radiation and contaminants.

Abstract: A method of minimizing contamination of optical components of a laser resonator is disclosed. The resonator components are located in an enclosure, which may contain contaminants including water vapor and organic favor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a desiccant, an organic vapor trapping material, and a particulate matter filter then returns the extracted gas to the enclosure. The purging system is particularly useful for ultrafast lasers and ultraviolet lasers where the power of the laser radiation increases the probability of destabilizing reactions between laser radiation and contaminants.

Abstract: A method of minimizing contamination of optical components of a laser resonator is disclosed. The resonator components are located in an enclosure, which may contain contaminants including water vapor and organic favor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a desiccant, an organic vapor trapping material, and a particulate matter filter then returns the extracted gas to the enclosure. The purging system is particularly useful for ultrafast lasers and ultraviolet lasers where the power of the laser radiation increases the probability of destabilizing reactions between laser radiation and contaminants.

Abstract: A method of operating a laser is disclosed. Components of the laser are located in an enclosure, which may contain contaminants including water vapor and organic vapor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter and ozone. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a catalyst to decompose the ozone, a desiccant, an organic vapor trapping material, and a particulate matter filter, then returns the extracted gas to the enclosure. Decomposing ozone is particularly important if the laser generates radiation at a wavelength less than 250 nm.

Abstract: A method of operating a laser is disclosed. Components of the laser are located in an enclosure, which may contain contaminants including water vapor and organic vapor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter and ozone. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a catalyst to decompose the ozone, a desiccant, an organic vapor trapping material, and a particulate matter filter, then returns the extracted gas to the enclosure. Decomposing ozone is particularly important if the laser generates radiation at a wavelength less than 250 nm.

Abstract: A laser system includes a laser for generating seed pulses, and a regenerative amplifier for amplifying seed pulses generated by the seed pulse laser. The regenerative amplifier includes a gain-element pumped by optical pump pulses delivered by a pump laser, and an optical switch controlled synchronously with the delivery of pump-pulses such that amplified seed pulses can be delivered in a desired sequence different from but related to a constant rate at which optical pump pulses are delivered to the regenerative amplifier.

Abstract: A method of delivering a seed-pulse to a regenerative amplifier includes generating an ultrashort optical pulse. The ultrashort optical pulse is delivered to a single-mode optical fiber configured to generate a continuum. A portion of the continuum generated by the optical fiber is selected by a pulse stretcher and converted into the seed pulse. The pulse stretcher can be tuned to provide seed pulses of selectively variable wavelength.

Abstract: An automatically-tunable, ultrafast laser delivers ultrashort pulses having a duration a few picoseconds or less. The laser has a laser resonator including an optically-pumped gain-medium providing optical gain over a gain-bandwidth characteristic of the gain-medium. The resonator includes one or more groups of group-delay-dispersion compensating prisms. One or more prisms in each group is moveable with respect to one or more others. A stop is arranged, cooperative with the group of prisms, to select a pulse wavelength within the gain-bandwidth. Tuning of the selected pulse-wavelength is accomplished by moving the moveable prism or prisms cooperative with the stop. The prism motion and the spatial relationship of the prisms with the stop is arranged such that the optical path length in the prisms for all selected lasing wavelengths is about the same. This provides that changes in characteristics of the output-pulses are minimized as the pulse wavelength is varied.

Abstract: A method of delivering a seed-pulse to a regenerative amplifier includes generating an ultrashort optical pulse. The ultrashort optical pulse is delivered to a single-mode optical fiber configured to generate a continuum. A portion of the continuum generated by the optical fiber is selected by a pulse stretcher and converted into the seed pulse. The pulse stretcher can be tuned to provide seed pulses of selectively variable wavelength.

Abstract: A method of minimizing contamination of optical components of a laser resonator is disclosed. The resonator components are located in an enclosure, which may contain contaminants including water vapor and organic favor released by the optical components, mounts of the optical components, or the enclosure itself. The enclosure may also contain suspended particulate matter. In order to reduce the level of these contaminants, a purging system extracts gas from the enclosure and passes the gas through a desiccant, an organic vapor trapping material, and a particulate matter filter then returns the extracted gas to the enclosure. The purging system is particularly useful for ultrafast lasers and ultraviolet lasers where the power of the laser radiation increases the probability of destabilizing reactions between laser radiation and contaminants.

Abstract: An automatically-tunable, ultrafast laser delivers ultrashort pulses having a duration a few picoseconds or less. The laser has a laser resonator including an optically-pumped gain-medium providing optical gain over a gain-bandwidth characteristic of the gain-medium. The resonator includes one or more groups of group-delay-dispersion compensating prisms. One or more prisms in each group is moveable with respect to one or more others. A stop is arranged, cooperative with the group of prisms, to select a pulse wavelength within the gain-bandwidth. Tuning of the selected pulse-wavelength is accomplished by moving the moveable prism or prisms cooperative with the stop. The prism motion and the spatial relationship of the prisms with the stop is arranged such that the optical path length in the prisms for all selected lasing wavelengths is about the same. This provides that changes in characteristics of the output-pulses are minimized as the pulse wavelength is varied.

Abstract: An apparatus for maintaining the temperature stability of an amplifier system comprises a device for heating, cooling or heating an cooling one or more sub-assemblies of the amplifier system, a temperature sensor for detecting variations in temperature of a sub-assembly, and a controller operably connecting the two. The signal from the sensor is used by the controller to adjust the amount of heating, cooling, or heating and cooling of a sub-assembly in order to maintain its temperature within a range sufficiently small to ensure stable performance.

Abstract: An ultrashort optical pulse amplifier that incorporates a gain medium preferentially cooled along a crystalline axis for partially ameliorating the thermally induced distortions and losses created by cylindrically symmetric cooled designs. The ultrashort pulse amplifier can be pumped with higher pump powers without degradation of the output spatial mode structure and the overall efficiency of extraction of energy from the gain medium is improved. The gain medium preferably has a rectangular cross section and cooling means are provided in thermal contact with only selected opposing surfaces of the gain medium so that thermal gradients lie approximately along a crystalline axis to reduce thermally-induced birefringence.

Abstract: A regenerative amplifier includes a resonant cavity having a gain medium and a spectral filter located in the cavity. A source is provided to pump the gain medium and thereby raise it to an excited state. Elements are also provided for creating laser seed pulses which are then injected into the resonant cavity, these elements preferably include in part a mode-locked oscillator having a wavelength substantially the same as that at which the gain medium can support amplification of the energy of the injected pulse. In a preferred embodiment the gain medium is Ti:Sapphire for both the amplifier and oscillator. Also, in the preferred embodiment the seed pulse from the oscillator is stretched in time by multiplicative factors sufficient to ensure that upon amplification, the seed pulse power density remains below the self-focusing threshold of the material through which the pulse is passed.

Abstract: An apparatus for stretching or compressing an ultrashort pulse in time that is free of non-linear and spatial distortion (temporal or spatial frequency chirp) comprises a first diffraction grating G, a concave spherically curved mirror [CCM] with a radius of curvature R.sub.1, a convex spherically curved mirror [CXM] with a radius of curvature R.sub.2, and a flat reflector, [PM]. As a result of propagation of the ultrashort input pulse through this system, the output pulse is either stretched (or compressed) in time so that it now has a duration many times longer (or many times shorter) than its input pulse duration, is spatially uniform (i.e. has no spatial chirp,) and collimated. It can be separated from the input pulse by passage through a Faraday isolator.

Abstract: A regenerative amplifier includes a resonant cavity having a gain medium and a spectral filter located in the cavity. A source is provided to pump the gain medium and thereby-raise it to an excited state. Elements are also provided for creating laser seed pulses which are then injected into the resonant cavity, these elements preferably include in part a mode-locked oscillator having a wavelength substantially the same as that at which the gain medium can support amplification of the energy of the injected pulse. In a preferred embodiment the gain medium is Ti:Sapphire for both the amplifier and oscillator. Also, in the preferred embodiment the seed pulse from the oscillator is stretched in time by multiplicative factors sufficient to ensure that upon amplification, the seed pulse power density remains below the self-focusing threshold of the material through which the pulse is passed.

Abstract: A composite having third order non-linear optical activity comprising, an organic polymer and an inorganic material. The organic polymer has third order nonlinear optical activity and the inorganic material is a sol-gel glass. The organic polymer or a precursor of the organic polymer is mutually soluble with a precursor of the sol-gel glass. The invention also includes photonic media having the above composite and a method of making the composite.