Abstract: A localized laser-based interceptor for kites balloons and UAVs comprises a laser and a large aperture optical beam delivery system with adjustable focal distance and spot size. The spot-size is adjusted for optimal damage performance on plastic targets, as a function of the distance from the target, its velocity across the laser beam spot and where the extent of the danger zone for personnel and equipment is limited by the fast expansion of the illuminating laser beams. The optical design ensures diverging beam to minimize the hazardous range of the system.

Abstract: A localized laser-based interceptor for kites balloons and UAVs comprises a laser and a large aperture optical beam delivery system with adjustable focal distance and spot size. The spot-size is adjusted for optimal damage performance on plastic targets, as a function of the distance from the target, its velocity across the laser beam spot and where the extent of the danger zone for personnel and equipment is limited by the fast expansion of the illuminating laser beams. The optical design ensures diverging beam to minimize the hazardous range of the system.

Abstract: A method for obtaining transient Bragg gratings in optical waveguides and several different applications of the transient Bragg gratings obtained using this method are presented. The basic mechanisms for obtaining the transient gratings in the waveguides are refractive index change due to Kerr nonlinearity, free carrier generation, and gratings formed by linear or non-linear absorption of thermal energy. The exemplary applications include an ultra-fast fiber laser source at any central wavelength, a fast spectral switch/modulator, transient pulse stretchers based on transient chirped gratings, Q-switching based on transient gratings, and time reversal of ultra-short pulses and low power sub-nanosecond pulse generations.

Abstract: The invention is optical configurations for constructing laser oscillators or laser amplifiers that comprise an extremely short fiber (typically tens of cm long or below, e.g. 5 cm to 30 cm). In order to overcome the absorption limitation due to the very short length of the fiber, the present invention employs a multi pump-pass scheme for pump light confinement. This scheme is based on the small angular overlap between the lasing and pump beams. The multi pump-pass method of the invention leads to efficient fiber laser oscillators and amplifiers having pulse duration of a few ns, with high average and peak power output that is comparable to the state-of-the-art solid state lasers.

Abstract: A method for obtaining transient Bragg gratings in optical waveguides and several different applications of the transient Bragg gratings obtained using this method are presented. The basic mechanisms for obtaining the transient gratings in the waveguides are refractive index change due to Kerr nonlinearity, free carrier generation, and gratings formed by linear or non-linear absorption of thermal energy. The exemplary applications include an ultra-fast fiber laser source at any central wavelength, a fast spectral switch/modulator, transient pulse stretchers based on transient chirped gratings, Q-switching based on transient gratings, and time reversal of ultra-short pulses and low power sub-nanosecond pulse generations.

Abstract: The invention is an active double-clad fiber comprising the following four layers: a high refractive index small diameter core; an inner annular clad layer doped with active ions surrounding the core; an outer annular clad layer surrounding the inner clad layer; and an annular low refractive index outer coating layer surrounding the outer clad layer. The structure of the fiber of the invention and the properties of the materials of its layers provides high discrimination against higher modes, thereby maintaining single mode operation in laser systems. The diameter of the core of the fiber of the invention is much smaller than the diameter of the large single transverse mode that it guides, thereby allowing guiding and amplification to take place mainly in the inner doped clad layer.

Abstract: The invention is an active double-clad fiber comprising the following four layers: a high refractive index small diameter core; an inner annular clad layer doped with active ions surrounding the core; an outer annular clad layer surrounding the inner clad layer; and an annular low refractive index outer coating layer surrounding the outer clad layer. The structure of the fiber of the invention and the properties of the materials of its layers provides high discrimination against higher modes, thereby maintaining single mode operation in laser systems. The diameter of the core of the fiber of the invention is much smaller than the diameter of the large single transverse mode that it guides, thereby allowing guiding and amplification to take place mainly in the inner doped clad layer.

Abstract: The invention is an apparatus and method for free space pumping of active double-clad fiber based lasers and amplifiers. The apparatus comprises a laser emitting a signal laser beam; an active double-clad fiber having a core defining an optical axis of the apparatus and a pump cladding defining a cone of numerical aperture; an optical arrangement directing the signal laser beam along the optical axis through the core of the active double-clad fiber; at least one pump source emitting a pump beam; at least one delivery means coupling the pump beam to the pump cladding of the active double-clad fiber; and an optical arrangement coupling the amplified signal laser beam exiting the active double-clad fiber out of the apparatus.

Abstract: The invention is an apparatus and method for free space pumping of active double-clad fiber based lasers and amplifiers. The apparatus comprises a laser emitting a signal laser beam; an active double-clad fiber having a core defining an optical axis of the apparatus and a pump cladding defining a cone of numerical aperture; an optical arrangement directing the signal laser beam along the optical axis through the core of the active double-clad fiber; at least one pump source emitting a pump beam; at least one delivery means coupling the pump beam to the pump cladding of the active double-clad fiber; and an optical arrangement coupling the amplified signal laser beam exiting the active double-clad fiber out of the apparatus.

Abstract: A resonator cavity (10A) and method are provided. The resonator cavity (10A) includes at least one gain medium (16) and end reflectors (12, 14) which define together longitudinal modes of light in the cavity, and further includes an intra-cavity beam coupler assembly (20). The beam coupler assembly (20) is configured to split light impinging thereon into a predetermined number of spatially separated light channels, and to cause phase locking and at least partial coherent combining of the light channels, having common longitudinal and transverse modes, in a double pass through the beam coupler assembly (20). The resonator cavity (10A) is configured and operable to produce at least one output combined light channel of a predetermined intensity profile.

Abstract: A resonator cavity (10A) and method are provided. The resonator cavity (10A) includes at least one gain medium (16) and end reflectors (12, 14) which define together longitudinal modes of light in the cavity, and further includes an intra-cavity beam coupler assembly (20). The beam coupler assembly (20) is configured to split light impinging thereon into a predetermined number of spatially separated light channels, and to cause phase locking and at least partial coherent combining of the light channels, having common longitudinal and transverse modes, in a double pass through the beam coupler assembly (20). The resonator cavity (10A) is configured and operable to produce at least one output combined light channel of a predetermined intensity profile.

Abstract: A resonator cavity (10A) and method and presented. The resonator cavity (10A) comprises at least one gain medium (16) and end reflectors (12, 14) which define together longitudinal modes of light in the cavity, and further comprises an intra-cavity beam coupler assembly (20). The beam coupler assembly (20) is configured to split light impinging thereon into a predetermined number of spatially separated light channels, and to cause phase locking and at least partial coherent combining of the light channels, having common longitudinal and transverse modes, in a double pass through the beam coupler assembly (20). The resonator cavity (10A) is configured and operable to produce at least one output combined light channel of a predetermined intensity profile.

Abstract: A resonator cavity (10A) and method and presented. The resonator cavity (10A) comprises at least one gain medium (16) and end reflectors (12, 14) which define together longitudinal modes of light in the cavity, and further comprises an intra-cavity beam coupler assembly (20). The beam coupler assembly (20) is configured to split light impinging thereon into a predetermined number of spatially separated light channels, and to cause phase locking and at least partial coherent combining of the light channels, having common longitudinal and transverse modes, in a double pass through the beam coupler assembly (20). The resonator cavity (10A) is configured and operable to produce at least one output combined light channel of a predetermined intensity profile.