Abstract: An optical fiber laser coupler, comprising a laser input optical cable, a laser shaping and coupling device, and a multi-beam-mode energy transmission fiber (205). The multi-beam-mode energy transmission fiber (205) comprises a circular fiber core (105) and annular fiber cores (106, 107), and each annular fiber core (106, 107) is coaxial with the circular fiber core (105). A fluorine-doped layer (109) is disposed between the circular fiber core (105) and the annular fiber core (106, 107), and the fluorine-doped layer (109) is also disposed between adjacent annular fiber cores (106, 107). An adjustable collimating lens group (203) and an adjustable focusing lens group (204) of the laser shaping and coupling device can horizontally move along a direction of a laser beam in a housing of the laser shaping and coupling device.

Abstract: An optical fiber laser coupler, comprising a laser input optical cable, a laser shaping and coupling device, and a multi-beam-mode energy transmission fiber (205). The multi-beam-mode energy transmission fiber (205) comprises a circular fiber core (105) and annular fiber cores (106, 107), and each annular fiber core (106, 107) is coaxial with the circular fiber core (105). A fluorine-doped layer (109) is disposed between the circular fiber core (105) and the annular fiber core (106, 107), and the fluorine-doped layer (109) is also disposed between adjacent annular fiber cores (106, 107). An adjustable collimating lens group (203) and an adjustable focusing lens group (204) of the laser shaping and coupling device can horizontally move along a direction of a laser beam in a housing of the laser shaping and coupling device.

Abstract: A method for preventing feedback light of a laser, includes fusion-splicing a target fiber to an output fiber of a laser, so that laser lights generated by the laser are output from the target fiber. A refractive index of a core of the output fiber of the laser is less than a refractive index of a core of the target fiber. When a feedback light of a laser light of the laser is reversely transmitted to a fusion-splicing surface through the target fiber, total reflection occurs due to a refractive index difference on the fusion-splicing surface, so that the feedback light is transmitted along the transmission direction of the laser light, and is prevented from entering the output fiber along the reverse direction of the laser light and further entering the laser's resonant cavity to damage the laser component or burn out the gain fiber.

Abstract: A multi-module fiber laser capable of monitoring abnormalities of optical modules in real time. In the multi-module fiber laser, the CAN bus is employed to directly obtain whether each of the slave control modules or the master control module is in normal working condition, so that the CAN bus is at the status level corresponding to whether all modules are in normal working state, namely, the CAN bus that is configured to transmit the light control signal issued by the master control module. The status level of the slave control module or the combiner module is also transmitted via the CAN bus, so that all the slave control modules can quickly put themselves in the corresponding working state according to the status level of the CAN bus.

Abstract: A wavelength division multiplexing device and method includes two prisms having a pair of coated, highly reflective opposed faces forming an etalon. A volume phase grating is sandwiched between the two prisms. The volume phase grating is positioned between the highly reflective opposed face portions so that a light beam incident on the etalon undergoes a preselected number of multiple reflections between the highly reflective face portions and a preselected number of traversals through the volume diffraction grating, whereby wavelengths satisfying a Bragg condition on each traversal are diffracted out of the volume grating means. One prism may be designed to separate TE and TM polarized light, and the other prism may be designed to combine the TE and TM modes so that the result is polarization independent. Each prism includes at least one transparent output face through which the separately diffracted wavelengths are transmitted at respective angles.