An electrodeless laser-driven light source includes a laser that generates a CW sustaining light. A pump laser generates pump light. A Q-switched laser crystal receives the pump light generated by the pump laser and generates pulsed laser light at an output in response to the generated pump light. A first optical element projects the pulsed laser light along a first axis to a breakdown region in a gas-filled bulb comprising an ionizing gas. A second optical element projects the CW sustaining light along a second axis to a CW plasma region in the gas-filled bulb comprising the ionizing gas. A detector detects plasma light generated by a CW plasma and generates a detection signal at an output. A controller generates control signals that control the pump light to the Q-switched laser crystal so as to extinguish the pulsed laser light within a time delay after the detection signal exceeds a threshold level.

A passively, Q-switched laser operating at an eye safe wavelength of between 1.2 and 1.4 microns is described. The laser may operate at a lasing wavelength of 1.34 microns and use a gain element of Nd:YVO.sub.4 and a saturable absorber element of V:YAG. The systems and methods to produce short pulses having a pulse duration less than 1 ns and high energy pulses having pulse energies greater than 2 μJ are described.

A photonic lantern couples light from several fibers or fiber cores into one or more fibers or fiber cores. Photonic lanterns are often used to combine several lower-power beams into a single higher-power beam. They can also be used to couple light from multi-core fibers into single-mode, multi-mode, or other multi-core fibers. By modulating the phases of the input beams, the light can be switched from output to output—for example, between output cores of a multi-core output fiber. If desired, the beams can also be amplified using an active fiber in or coupled to the photonic lantern. A first photonic lantern couples signal light and pump light into the core and cladding, respectively, of an active multi-mode or multi-core fiber. And the active multi-mode or multi-core fiber couples amplified signal light into output fiber(s) via a second photonic lantern.

A photonic lantern couples light from several fibers or fiber cores into one or more fibers or fiber cores. Photonic lanterns are often used to combine several lower-power beams into a single higher-power beam. They can also be used to couple light from multi-core fibers into single-mode, multi-mode, or other multi-core fibers. By modulating the phases of the input beams, the light can be switched from output to output—for example, between output cores of a multi-core output fiber. If desired, the beams can also be amplified using an active fiber in or coupled to the photonic lantern. A first photonic lantern couples signal light and pump light into the core and cladding, respectively, of an active multi-mode or multi-core fiber. And the active multi-mode or multi-core fiber couples amplified signal light into output fiber(s) via a second photonic lantern.

An electrodeless laser-driven light source includes a laser that generates a CW sustaining light. A pump laser generates pump light. A Q-switched laser crystal receives the pump light generated by the pump laser and generates pulsed laser light at an output in response to the generated pump light. A first optical element projects the pulsed laser light along a first axis to a breakdown region in a gas-filled bulb comprising an ionizing gas. A second optical element projects the CW sustaining light along a second axis to a CW plasma region in the gas-filled bulb comprising the ionizing gas. A detector detects plasma light generated by a CW plasma and generates a detection signal at an output. A controller generates control signals that control the pump light to the Q-switched laser crystal so as to extinguish the pulsed laser light within a time delay after the detection signal exceeds a threshold level.

A laser oscillator includes a first structure disposed with an optical section, a second structure disposed with a power source section, and an electric cable that electrically connects the optical section and the power source section. The first structure is removably coupled to the second structure, the electric cable is removably connected to at least one of the power source section and the optical section, and the optical section is allowed to be replaced.

A class of erbium-doped silicate crystals have a general chemical formula of (Er.sub.xYb.sub.yCe.sub.zA.sub.(1-x-y-z)).sub.3RM.sub.3Si.sub.2O.sub.14, in which the range of x is 0.002 to 0.02, y is 0.005 to 0.1, and z is 0 to 0.15; A is one, two or three elements selected from Ca, Sr, or Ba; R is one or two elements selected from Nb or Ta; M is one or two elements selected from Al or Ga. Using one of such crystals as a gain medium and a diode laser at 940 nm or 980 nm as a pumping source, a 1.5 μm continuous-wave solid-state laser with high output power and high efficiency, as well as a pulse solid-state laser with high energy and narrow width can be obtained.

A class of erbium-doped silicate crystals have a general chemical formula of (Er.sub.xYb.sub.yCe.sub.zA.sub.(1-x-y-z)).sub.3RM.sub.3Si.sub.2O.sub.14, in which the range of x is 0.002 to 0.02, y is 0.005 to 0.1, and z is 0 to 0.15; A is one, two or three elements selected from Ca, Sr, or Ba; R is one or two elements selected from Nb or Ta; M is one or two elements selected from Al or Ga. Using one of such crystals as a gain medium and a diode laser at 940 nm or 980 nm as a pumping source, a 1.5 μm continuous-wave solid-state laser with high output power and high efficiency, as well as a pulse solid-state laser with high energy and narrow width can be obtained.

The present invention is to provide a backscattered light amplification device, an optical pulse test apparatus, a backscattered light amplification method, and an optical pulse test method for amplifying a desired propagation mode of Rayleigh backscattered light with a desired gain by stimulated Raman scattering in a fiber under test having the plurality of propagation modes. The backscattered light amplification device according to the present invention is configured to control individually power, incident timing, and pulse width of a pump pulse for each propagation mode when the pump pulse is incident in a plurality of propagation modes after the probe pulse is input to the fiber under test in any propagation mode.

A photonic device is configured with a photonic integrated circuit (PIC), a plurality of fiber-based gain mediums in optical communication with the PIC, and at least one optical pump outputting pump light coupled into two or more gain mediums. At least one of the fiber-based gain media and the PIC form a hybrid resonant optical cavity there between operative to lase light into the PIC. The gain media further include one or more fiber amplifiers amplifying light signals coupled into and decoupled from the PIC. The photonic device is integrated with Si photonic passive and active photonic elements, while ail fiber links between the gain media and PIC are free from these elements.