Abstract: A STED microscope for producing a 3D image. The microscope has an excitation laser source for providing an excitation laser beam and a depletion laser source for providing stimulated emission depletion laser beam. The excitation beam is capable of exciting fluorescent markers in a sample placed in the sample region and the depletion beam is capable of inducing stimulated emission in the fluorescent marker in the sample in a region around the excitation beam to restrict the size of the region within which the fluorescent markers are excited and wherein the depletion laser source goes through an optical element which creates a cone refractive pattern which induces stimulated emission in the fluorescent marker in the sample. The shape of the light hollow of the cone refractive pattern varies at different distances from the source. This depth profile can be used to distinguish between positions at varying depths within a sample to create a 3D image.

Abstract: Aspects of the present disclosure relate to the field of laser technology, specifically semiconductor lasers, and to novel biomedical applications of such lasers, including novel methods of photodynamic therapy. Exemplary embodiments of the present disclosure include a semiconductor laser diode having an active region having a gain medium with one or more InGaAs/InAs quantum dot layers; and wherein the laser diode can be arranged in operation to emit laser light having a central wavelength within spectral range of wave lengths. The present embodiments further include a method of directly forming a reactive oxygen species (ROS), the method including exposing a medium having a potential source of ROS to a semiconductor laser diode, the semiconductor laser diode configured to emit laser light having a central wavelength within the spectral range.

Abstract: A STED microscope for producing a 3D image. The microscope has an excitation laser source for providing an excitation laser beam and a depletion laser source for providing stimulated emission depletion laser beam. The excitation beam is capable of exciting fluorescent markers in a sample placed in the sample region and the depletion beam is capable of inducing stimulated emission in the fluorescent marker in the sample in a region around the excitation beam to restrict the size of the region within which the fluorescent markers are excited and wherein the depletion laser source goes through an optical element which creates a cone refractive pattern which induces stimulated emission in the fluorescent marker in the sample. The shape of the light hollow of the cone refractive pattern varies at different distances from the source. This depth profile can be used to distinguish between positions at varying depths within a sample to create a 3D image.

Abstract: Aspects of the present disclosure relate to the field of laser technology, specifically semiconductor lasers, and to novel biomedical applications of such lasers, including novel methods of photodynamic therapy. Exemplary embodiments of the present disclosure include a semiconductor laser diode having an active region having a gain medium with one or more InGaAs/InAs quantum dot layers; and wherein the laser diode can be arranged in operation to emit laser light having a central wavelength within spectral range of wave lengths. The present embodiments further include a method of directly forming a reactive oxygen species (ROS), the method including exposing a medium having a potential source of ROS to a semiconductor laser diode, the semiconductor laser diode configured to emit laser light having a central wavelength within the spectral range.

Abstract: A photoconductive device (2) comprises a plurality of photoconductive layers (6, 8, 10, 12), each photoconductive layer comprising photoconductive material (4) and a respective plurality of electrodes (16, 18), wherein the photoconductive layers (6, 8, 10, 12) are electrically connected together.