Abstract:
A mode locked pulsed laser incorporates an intracavity element to compensate for the dispersion caused by other intracavity elements. This element reduces the tendency of the pulse to broaden in the cavity due to group velocity dispersion and results in very short pulses. In the laser of the present invention, mode locking is initiated by detecting the beat frequency between adjacent longitudinal modes using a high speed photodiode. This signal is amplified and then the frequency is divided by two. The signal is passed through an electronically adjustable phase shifter and then to a power amplifier. This signal is applied to the acousto-optic modelocker. If the cavity length drifts the beat frequency between the longitudinal modes changes. The rf signal applied to the modulator changes in exactly the right manner to track the drift in cavity length. Thus the modelocker is automatically synched to the round trip of the laser cavity.
Abstract:
A compact laser head for a solid state laser has a miniaturized laser rod and output coupling mirror which form a miniaturized laser cavity. A miniaturized frequency doubler crystal placed in the cavity provides frequency doubled output. The laser head is connected by an optical fiber to a separate power supply which contains a laser diode pumping source. A quick disconnect connector enables the fiber optic to be easily connected to the laser head. Pumping radiation is transmitted through the optical fiber to longitudinally end pump the laser rod using fiber coupling imagery. The fiber is aligned with the rod by the connector and the pumping radiation is imaged into the rod by a focussing sphere. The pumping volume is matched to the lasing volume which is determined by the cavity geometry. The quick disconnect laser head allows interchange of different heads with different output characteristics while using a single power supply.
Abstract:
A neodymium YAG laser is pumped by a matched laser diode of high efficiency, resulting in a compact, high-efficiency and long-lifetime laser assembly. Output is in the near infrared range, but can be converted to the visible spectrum by an internal frequency doubler. A doubling crystal, which may be a KTP crystal, is placed at an optimum location in the laser cavity. Polarization of the beam may be achieved simply by stressing the YAG rod, prior to frequency doubling.
Abstract:
A neodymium or other rare earth doped solid state laser is pumped by a matched high efficiency laser diode, resulting in a compact, high efficiency and long lifetime laser assembly. Output is in the near infrared range, but can be converted to the visible spectrum by an intra-cavity frequency doubler. A doubling crystal, which may be a KTP crystal, is placed at an optimum location in the laser cavity. Polarization of the beam may be achieved simply by stressing a non-birefringent rod, prior to frequency doubling, or by using a birefringent material such as Nd:YLF for the rod. An amplitude noise suppression etalon may also be placed at an optimum position in the laser cavity; alternatively a ring cavity or pair of quarter wave plates can be used. A folded cavity configuration produces a pair of beam waists in the cavity. Pulsed operation can be produced by means of a Q-switch.
Abstract:
The ellipticity of a thermal lens is controlled in a diode-pumped anisotropic crystal, such as Nd:YVO4. The crystal has two opposing optical end faces through which a pump beam and an output beam pass. The crystal also has opposing "c" axis crystal faces normal to a "c" axis of the crystal, and opposing "a" axis crystal faces that are normal to an "a" axis of the crystal. A mount supports the crystal and serves as a heat sink. A path is created to conduct heat from the crystal through the "c" faces, while the "a" faces are thermally isolated from heat conduction. The thermal lens ellipticity is controlled in order to produce a round, diffraction limited gaussian beam suitable for applications that require a high power, good quality beam from a simple, reliable laser source.
Abstract:
A small diameter multimode optical fiber with a low numerical aperture (i.e., 0.1) is used as a microlens to collimate the output emissions of a laser diode before butt coupling the output of the laser diode to an optical fiber. The optical fiber used as the microlens is chosen such that its diameter roughly equals the diameter of the fiber to be coupled to the laser diode. The collimation is performed in the high NA direction of the output of the laser diode. The output of a bundle of butt coupled optical fibers may be used to pump a laser system.
Abstract:
A neodymium or other rare earth doped solid state laser is pumped by a matched high efficiency laser diode, including a diode array and a multi-spatial mode extended emitter diode, resulting in a compact, high efficiency and long lifetime laser assembly. The cavity mode volume is matched to a region of absorption in the pumping volume formed by the focused diode beam. Output is in the near infrared range, but can be converted to the visible spectrum by an intra-cavity frequency doubler. A doubling crystal, e.g. KTP, is placed in an optimum location in the laser cavity. Polarization of the beam for frequency doubling may be achieved by using a birefringent material for the rod or by stressing a non-birefringent rod. An amplitude noise suppression etalon may also be placed at an optimum position in the laser cavity. A folded cavity configuration produces a pair of beam waists in the cavity. Pulsed operation can be produced by means of a Q-switch.
Abstract:
A neodymium or other rare earth doped solid state laser is pumped by a matched high efficiency laser diode, resulting in a compact, high efficiency and long lifetime laser assembly. Output is in the near infrared range, but can be converted to the visible spectrum by an intra-cavity frequency doubler. A doubling crystal, which may be a KTP crystal, is placed at an optimum location in the laser cavity. Polarization of the beam may be achieved simply by stressing a non-birefringent rod, prior to frequency doubling, or by using a birefringent material such as Nd:YLF for the rod. An amplitude noise suppression elaton may also be placed at an optimum position in the laser cavity; alternatively a ring cavity or pair of quarter wave plates can be used. A folded cavity configuration produces a pair of beam waists in the cavity. Pulsed operation can be produced by means of a Q-switch.
Abstract:
A compact laser head for a solid state laser has a miniaturized laser rod and output coupling mirror which form a miniaturized laser cavity. A miniaturized frequency doubler crystal placed in the cavity provides frequency doubled output. The laser head is connected by an optical fiber to a separate power suply which contains a laser diode pumping source. A quick disconnect connector enables the fiber optic to be easily connected to the laser head. Pumping radiation is transmitted through the optical fiber to longitudinally end pump the laser rod using fiber coupling imagery. The fiber is aligned with the rod by the connector and the pumping radiation is imaged into the rod by a focussing sphere. The pumping volume is matched to the lasing volume which is determined by the cavity geometry. The quick disconnect laser head allows interchange of different heads with different output characteristics while using a single power supply.
Abstract:
A diode-pumped solid-state laser has been invented that provides long Q-switched pulses at high repetition rate with high stability. The laser incorporates Nd:YVO4 as the gain medium.