摘要:
Systems and methods are provided for imaging using complex lasers. In general, a complex laser may be used as an electromagnetic source for an imaging application. The use of a lower spatial coherence configured complex laser in imaging applications may advantageously mitigate coherent artifacts in imaging such as cross-talk and speckle and improve overall image quality. Imaging applications where a complex laser may be useful include both incoherent imaging applications, such as digital light projectors and traditional microscopy, and coherent imaging applications, such as optical coherence tomography (OCT) and holography. The systems and methods provided also enable controlling the degree of spatial coherence of a complex laser.
摘要:
A method and apparatus for controlling the amplification of radiation in a laser gain are described. By using the controlling action of a secondary radiation path through the common gain element the gain, as seen by the primary radiation path, can be controlled or limited. In one particularly set of embodiments pertaining to laser pulse control of a laser cavity, a laser system is described that comprises first and second laser cavities each including a common laser gain medium. The first cavity incorporates a modulation element for variation of its cavity loss. A second cavity is employed that has a substantially distinct path or separable cavity mode from that of the first cavity. The laser threshold of the second cavity is set to a value intermediate to the extremes of the threshold for the first cavity, corresponding to the maximum and minimum loss available to the modulation element. As a result a more flexible control of laser pulsing and laser performance control is provided. Other embodiments of this invention allow improvement of laser performance through the control of the amplification of the output of a laser system through an external laser amplifier by utilising a secondary radiation path through the external amplifier.
摘要:
Es wird ein kantenemittierender Halbleiterlaser mit einem Halbleiterkörper (10) angegeben, der einen Wellenleiterbereich (4) aufweist, wobei der Wellenleiterbereich (4) eine erste Wellenleiterschicht (2A), eine zweite Wellenleiterschicht (2B) und eine zwischen der ersten Wellenleiterschicht (2A) und der zweiten Wellenleiterschicht (2B) angeordnete aktive Schicht (3) zur Erzeugung von Laserstrahlung (17) aufweist, der Wellenleiterbereich (4) zwischen einer ersten Mantelschicht (1A) und einer dem Wellenleiterbereich (4) in Wachstumsrichtung des Halbleiterkörpers (10) nachfolgenden zweiten Mantelschicht (1B) angeordnet ist, in dem Halbleiterkörper (10) eine Phasenstruktur (6) zur Selektion lateraler Moden der von der aktiven Schicht (3) emittierten Laserstrahlung ausgebildet ist, wobei die Phasenstruktur (6) mindestens eine Ausnehmung (7) umfasst, die sich von einer Oberfläche (5) des Halbleiterkörpers (10) in die zweite Mantelschicht (1B) hinein erstreckt, in die zweite Mantelschicht (1B) mindestens eine erste Zwischenschicht (11) aus einem von dem Halbleitermaterial der zweiten Mantelschicht (1B) verschiedenen Halbleitermaterial eingebettet ist, und sich die Ausnehmung (7) von der Oberfläche (5) des Halbleiterkörpers (10) zumindest teilweise bis in die erste Zwischenschicht (11) erstreckt.
摘要:
Es wird ein kantenemittierender Halbleiterlaser mit einem Halbleiterkörper (1), der einen Wellenleiterbereich (2) aufweist, angegeben. Der Wellenleiterbereich (2) weist eine untere Mantelschicht (3a), eine untere Wellenleiterschicht (4a), eine aktive Schicht (5) zur Erzeugung von Laserstrahlung, eine obere Wellenleiterschicht (4b) und eine obere Mantelschicht (3b) auf. Weiterhin weist der Wellenleiterbereich (2) mindestens einen strukturierten Bereich (6) zur Streuung der Laserstrahlung auf, in dem eine laterale Grundmode der Laserstrahlung geringere Streuverluste als die Strahlung höherer Lasermoden erfährt.
摘要:
Provided is a semiconductor laser diode having a waveguide lens. The semiconductor laser diode includes at least one first waveguide having a narrow width, at least one second waveguide having a wide width wider, and at least one waveguide lens having an increasing width from the first waveguide toward the second waveguide and connecting the first waveguide to the second waveguide. Sidewalls of the waveguide lens connecting the first waveguide to the second waveguide may be curved. The second waveguide may be a waveguide providing an optical gain.
摘要:
The present invention relates to a laser diode element comprising a semiconductor structure embedded in a cladding (34), said semiconductor structure comprising a p-type injection region (36-1) and an n-type injection region (36-2) for injecting current into an active resonator region (37), characterised in that said cladding (34) comprises a conductive material, preferably a metallic material.
摘要:
Optical gain of a nonpolar or semipolar Group-Ill nitride diode laser is controlled by orienting an axis of light propagation in relation to an optical polarization direction or crystallographic orientation of the diode laser. The axis of light propagation is substantially perpendicular to the mirror facets of the diode laser, and the optical polarization direction is determined by the crystallographic orientation of the diode laser. To maximize optical gain, the axis of light propagation is oriented substantially perpendicular to the optical polarization direction or crystallographic orientation.
摘要:
Disclosed is an example method to reduce waveguide scattering loss. The method includes forming a waveguide having a sidewall, the waveguide including a group III-V compound semiconductor material, and growing a native oxide on the waveguide to form an index of refraction contrast at the sidewall, the native oxide grown in a controlled Oxygen-enriched water vapor environment to reduce a roughness of the sidewall.