| 摘要 |
PURPOSE: To emit light as a directed beam with one-half wavelength of the predetermined wavelength from a device by containing a particular periodic grid construction for a clad layer and by forming so as to transmit light of almost one-half wavelength of the predetermined wavelength. CONSTITUTION: Clad layers (covering layers) 2 and 3 and active layer 1 are formed on a monocrystal gallium arsenic substrate 3 heavily doped with impurities. Next, a periodic diffraction grating 4 is formed on the second clad layer 3 so as to give a period ofΛ=mλ2 /n, a material of the clad layer 3 is fully removed at a trough 4a between peaks (crest value) 4b of a diffraction grating 4, a second clad layer 3 is made almost transparent for the light of 1/2 wavelength of the predetermined wavelength, and the light of wavelength ofλ2 is emitted in a vertical direction from the active layer 1 through a second clad layer 3. Here,λ2 is a 1/2 wavelength of the predetermined wavelength, m is the order of diffraction, or n is a refraction factor of one clad layer 3. By doing this, it can be emitted as a beam directed to 1/2 wavelength of the predetermined wavelength.
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