摘要 |
A medium having the function of light emission or optical amplification induced by optical pumping is surrounded by an annular laser (ring laser) having a diffraction grating (holographic structure) of the second order or more. The output of the ring laser emits through this diffraction grating (holographic structure) and is extracted as radiation mode. This is used as pumping light to be input to the medium that is disposed in the vicinity of the center of the assembly. To stabilize the threshold of the longitudinal mode, which has a greater amount of radiation mode, a gain medium and a reflective structure could be further provided around the periphery of this ring laser. This element also plays a role of optical pumping from the sides of a VCSEL.
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