Abstract: A method and apparatus for increasing the energy extraction efficiency from laser amplifiers by passing a laser signal through the amplifier multiple times in a collinear geometry without need to use active optical switching components. The invention uses a non-reciprocal optical element which affects (e.g., rotates the polarization of) a light beam differently depending on which direction the beam passes through the optical element. In a preferred embodiment, the method and apparatus employs a Faraday rotator as the direction-dependent light beam rotating device.

Abstract: A pulse compression and prepulse suppression apparatus (10) for time compressing the output of a laser (14). A pump pulse (46) is separated from a seed pulse (48) by a first polarized beam splitter (20) according to the orientation of a half wave plate (18). The seed pulse (48) is directed into an SBS oscillator (44) by two plane mirrors (22, 26) and a corner mirror (24), the corner mirror (24) being movable to adjust timing. The pump pulse (46) is directed into an SBS amplifier 34 wherein SBS occurs. The seed pulse (48), having been propagated from the SBS oscillator (44), is then directed through the SBS amplifier (34) wherein it sweeps the energy of the pump pulse (46) out of the SBS amplifier (34) and is simultaneously compressed, and the time compressed pump pulse (46) is emitted as a pulse output (52). A second polarized beam splitter (38) directs any undepleted pump pulse 58 away from the SBS oscillator (44).

Abstract: An apparatus and method for flattening the gain of an optical fiber amplifier (18) doped with an ion such as erbium and which is pumped by a pump laser (20). Optical couplers (32, 34) inserted before and after the fiber amplifier couple the main optical path to an optical ring passing through the fiber amplifier so as to form a ring laser. An optical isolator (32) placed in the ring causes the lasing light to only counterpropagate relative to the optical signal being amplified. When the fiber amplifier primarily exhibits inhomogeneous broadening and the ring lases, the lasing light clamps the gain to a value determined by the loop loss, and the value of the clamped gain is relatively uniform across a wide bandwidth.

Abstract: A method and apparatus for injecting a pump beam into a multi-pass amplifier to achieve a high degree of pump-input beam overlap.

Abstract: An optical signal amplifier with a waveguide path integrated into a glass body that is doped with optically active material. The signal to be amplified is transmitted through the waveguide and the pump power is coupled into the waveguide at one end. The waveguide comprises closely spaced adjacent guide lengths in the form of a spiral, zigzag paths between mirrors, or parallel paths with connecting semicircles at alternating ends of succeeding pairs of paths.

Abstract: A light amplifying device comprising an optical oscillator constituted by first and second reflective mirrors and a common reflective mirror disposed in an optically opposite relation to each other, a polarized beam splitter for making a laser beam incoming from the side of the common reflective mirror incident on the first or second reflective mirror, and for making laser beams incoming from the sides of the first and second reflective mirrors incident on the common mirror, first and second amplifying media disposed in optical paths of the respective laser beams for amplifying the laser beams, and an optical element for rotating the polarizing plane of the laser beam reflected by the common reflective mirror by a predetermined angle.