Abstract: A method and system for improving lateral resolution in optical microscopy are provided. The method includes generating a source optical beam and passing the source optical beam successively through an axicon, a Fourier-transform lens and an objective to convert the source optical beam into an excitation Bessel-type beam having a central lobe and at least one side lobe. The method also includes focusing the excitation beam onto a focal plane of the objective within or on a sample to generate a sample light signal, and spatially filtering the sample light signal. The spatial filtering includes rejecting light originating from outside of the focal plane and light generated by the at least one side lobe of the excitation beam. The spatial filtering also includes permitting passage, as a filtered light signal, of light generated by the central lobe of the excitation beam. The method further includes detecting the filtered light signal.

Abstract: A method and a system for obtaining a high-resolution image of a volume of a sample using laser imaging are provided. The method includes a step of probing the volume of the sample with a first excitation beam having an intensity profile of maximum intensity at a center thereof, thereby obtaining a positive image of the volume. The method also includes a step of probing the volume of the sample with a second excitation beam having an intensity profile of minimum intensity at a center thereof and defining a peripheral region of maximum intensity around the center, thereby obtaining a negative image of the volume. The method finally includes a step of subtracting the negative image from the positive image, thereby obtaining the high-resolution image of the volume of the sample. Advantageously, embodiments of the invention can be probe- and fluorescence-independent, and be conveniently retrofitted into existing laser imaging systems.

Abstract: A method and a system for obtaining a high-resolution image of a volume of a sample using laser imaging are provided. The method includes a step of probing the volume of the sample with a first excitation beam having an intensity profile of maximum intensity at a center thereof, thereby obtaining a positive image of the volume. The method also includes a step of probing the volume of the sample with a second excitation beam having an intensity profile of minimum intensity at a center thereof and defining a peripheral region of maximum intensity around the center, thereby obtaining a negative image of the volume. The method finally includes a step of subtracting the negative image from the positive image, thereby obtaining the high-resolution image of the volume of the sample. Advantageously, embodiments of the invention can be probe- and fluorescence-independent, and be conveniently retrofitted into existing laser imaging systems.

Abstract: A method for generating an ultrashort charged particle beam, comprising creating a high intensity longitudinal E-field by shaping and tightly focusing, in an on-axis geometry, a substantially radially polarized laser beam, and using the high intensity longitudinal E-field for interaction with a medium to accelerate charged particles.

Abstract: A protective baseboard for protecting a building wall in an industry requiring sanitary requirements. The protective baseboard is positionable substantially adjacent the ground surface. The protective baseboard includes a substantially rigid and substantially water proof casing. The casing defines a casing external wall, the casing external wall having a casing wall inner surface. The casing also defines a casing inner volume and a filling aperture extending therethrough. The casing is positionable in a predetermined relationship relative to the building wall. A filler is provided within the casing inner volume. The filler substantially contacts the casing inner surface for minimizing an amount of air between the filler and the casing external wall.

Abstract: There is described a method of characterizing a short laser pulse, the method comprising the steps of obtaining root-mean-square widths of the pulse through second order moments of the pulse; obtaining a spectral width of the pulse using the root-mean-square widths; obtaining a root-mean square temporal width of the pulse; and defining a Pulse Quality Factor proportional to a product of the spectral width and the temporal width. This approach does not require complete characterization of laser pulses and eliminates the need of any assumption to interpret autocorrelation traces. The method can be applied to pulses of arbitrary shape.

Abstract: A protective baseboard for protecting a building wall in an industry requiring sanitary requirements. The protective baseboard is positionable substantially adjacent the ground surface. The protective baseboard includes a substantially rigid and substantially water proof casing. The casing defines a casing external wall, the casing external wall having a casing wall inner surface. The casing also defines a casing inner volume and a filling aperture extending therethrough. The casing is positionable in a predetermined relationship relative to the building wall. A filler is provided within the casing inner volume. The filler substantially contacts the casing inner surface for minimizing an amount of air between the filler and the casing external wall.

Abstract: A novel method for high power optical amplification of ultrashort pulses in IR wavelength range (0.7-20 Ãm) is disclosed. The method is based on the optical parametric chirp pulse amplification (OPCPA) technique where a picosecond or nanosecond mode locked laser system synchronized to a signal laser oscillator is used as a pump source or alternatively the pump pulse is created from the signal pulse by using certain types of optical nonlinear processes described later in the document. This significantly increases stability, extraction efficiency and bandwidth of the amplified signal pulse. Further, we disclose five new practical methods of shaping the temporal and spatial profiles of the signal and pump pulses in the OPCPA interaction which significantly increases its efficiency. In the first, passive preshaping of the pump pulses has been made by a three wave mixing process separate from the one occurring in the OPCPA.

Abstract: Method of generating laser pulses using a semiconductor laser diode as a lasing amplification medium of an extended laser cavity are presented. Passive self-modulated mode-locked operation of the semiconductor laser diode is achieved by providing an above lasing threshold direct current input current to the semiconductor laser diode while the semiconductor laser diode is operational in a slightly misaligned extended laser cavity favoring the amplification of wavelengths shorter than a center wavelength of a continuous wave operational mode of the semiconductor laser diode at threshold.

Abstract: There is described a method of characterizing a short laser pulse, the method comprising the steps of obtaining root-mean-square widths of the pulse through second order moments of the pulse; obtaining a spectral width of the pulse using the root-mean-square widths; obtaining a root-mean square temporal width of the pulse; and defining a Pulse Quality Factor proportional to a product of the spectral width and the temporal width. This approach does not require complete characterization of laser pulses and eliminates the need of any assumption to interpret autocorrelation traces. The method can be applied to pulses of arbitrary shape.