摘要:
Apparatus (380) for providing optical radiation (381), which apparatus comprises a seed laser (382) for providing seeding radiation (387), at least one amplifier (383) for amplifying the seeding radiation (387), and a reflector (384), wherein the seed laser (382) is a Fabry Perot semiconductor laser, the seed laser (382) is connected to the amplifier (383) via the reflector (384), the reflector (384) is arranged to reflect a proportion (388) of the seeding radiation (387) emitted by file seed laser (382) back into the seed laser (382), and the amplifier (383) comprises an optical fibre (1) which comprises a core (3) having a refractive index n1 and a pedestal (4) having a refractive index n2, and wherein the optical fibre (1) includes a first cladding (5) made of glass having a refractive index n3 surrounding the pedestal (4), wherein n1 is greater than n2, and n2 is greater than n3.
摘要:
A plurality of active gain material (93) is disposed in an active interface portion (44) of a dielectric band-gap cladding confinement region (22) adjacent to a dielectric core (12) of a photonic band-gap crystal fiber (20), wherein during operation, the plurality of active gain material (93) absorbs the pump energy and stores the pump energy as a potential energy storage for stimulation by EM energy in a second guided mode at a second frequency in a second range of frequencies for overlapping with the first guided mode of the core (12) such that the surface defined by an interface between the photonic band-gap cladding (22) and the dielectric core (12) that supports at least one surface mode propagating at that interface (44) overlaps the active interface portion of the dielectric cladding confinement region and a state associated with the dielectric core (12).
摘要:
Non-linear effects in an optical fiber used for communicating AM signals at high power levels are reduced by increasing the linewidth of the pump laser output signal. The linewidth is increased by injecting spontaneous emissions into the laser cavity.
摘要:
Non-linear effects in an optical fiber used for communicating AM signals at high power levels are reduced by increasing the linewidth of the pump laser output signal. The linewidth is increased by injecting spontaneous emissions into the laser cavity.
摘要:
Non-linear effects in an optical fiber used for communicating AM signals at high power levels are reduced by increasing the linewidth of the pump laser output signal. The linewidth can be increased by optically broadening the laser output signal by driving an optical angle modulator with broadband electrical noise. The optical signal is then externally modulated with an AM information signal for transmission over an optical link fiber. The optical modulation can be provided using either an FM or PM optical modulator. A desired linewidth can be provided by controlling the optical modulation index during the optical modulation step and/or by controlling the bandwidth of the noise source. Other techniques for broadening a laser output signal, including modulating the signal by a periodic function such as a sine wave, or injecting spontaneous emissions into the laser cavity, are also disclosed.
摘要:
According to one aspect, the invention relates to a device comprising an optical fibre having a high Brillouin threshold, said device including an optical fibre (101) suitable for propagating a high-power optical signal beam, means (11) for coupling a signal beam to an entrance end of the optical fibre (101) and a tubular structure (10) comprising at least one first tube (103) and at least one first adhesive material (102). According to the present description, at least one portion of the optical fibre is immobilized in the tubular structure (10) by means of the first adhesive material (102), which adheres both to the internal surface of the first tube (103) and to the external surface of the optical fibre (101). Furthermore, at room temperature and with no other external stresses on the device, the immobilized portion of the optical fibre (101) is maintained in a compressive state by the tubular structure, the compressive state being such that the relative deformation of the optical fibre is negative or zero in its portion immobilized in the tubular structure, the maximum value of the relative deformation of the immobilized portion of the optical fibre being higher in absolute value than 0.3%.
摘要:
In various embodiments, an optical fiber (11) includes a core (42) having a relatively large area selected so as to raise a threshold of stimulated Raman scattering or stimulated Brillouin scattering, or both, the core (42) having a high aspect ratio elongated cross-section and having a first refractive index. The core is narrower in a fast-axis direction and wider in a slow-axis direction, such that the fiber is mechanically flexible in the fast-axis direction and is mechanically rigid in the slow-axis direction.
摘要:
The invention relates to a cladding-pumped optical device (40), comprising: an optical fibre (41) and pumps (44), wherein the optical fibre (41) comprises a core having a refractive index n1 and a pedestal having a refractive index n2, and wherein the optical fibre (41) includes a first cladding made of glass having a refractive index n3 surrounding the pedestal, wherein n1 is greater than n2, n2 is greater than n3, wherein the optical device (40) is cladding pumped by coupling pump radiation into at least the first cladding (5), and wherein signal light scattering or leaking from the core is captured and guided by the pedestal and therefore not routed back into the pumps (44).
摘要:
In a Raman system, a primary laser source emits laser light at an initial wavelength, and a seed source emits a multi-wavelength seed laser light. The seed wavelengths correspond to a respective Stokes orders of the primary laser light. The primary laser light and the seed laser light are combined and fed into a Raman gain medium. Stimulated Raman scattering (SRS) causes the primary laser light to be converted into laser light at a selected target wavelength. The seeding of the primary light source mediates the conversion process. An increase in conversion efficiency arises from the lower gain requirement and directionality of the described approach compared with an approach based on spontaneous Raman scattering.