Surface illuminating type light emitting diode

Abstract

Abstract PURPOSE:To improve connection efficiency to an optical fiber by providing the N layer having an index of refraction larger than that of substrate between the active layer and N type substrate, making maximum the thickness on the same center axis as that of light emitting region and providing the P layer in the area other than the light emitting region between the substrate and N layer. CONSTITUTION:The P-InP 22 is provided on the plane (100) of the N-InP sub- strate 21, it is etched in circular by the HCl+H3PO4, difference in shape at the cross-sections (0-1-1), (01-1) is alleviated by the melt-back in proper composition, and a smooth concave 24 can be formed. In succession, the electrodes 17, 18 are formed by stacking the N-InGaAs 23, N-InP 12, InGaAsP active layer 13, P-InP clad 14, and P<+> InGaAsP cap 15. The composition of layer 23 should be selected so that its Eg is larger than that of the active layer and it becomes transparent for the wavelength of light emitted. The light emitted from the restricted region of the active layer 13 is converted to the parallel light beam when the curvature of plane 23 of layer 23 is selected and it can be extracted efficently from the plane 25. Thereby, a diode can be coupled to optical fiber with a coupling efficiency near to the theoretical value while easing the alignment accuracy through the other lens system.

Inventors

• 👤 Kuniaki Iwamoto
• 👤 岩本　邦彬

Bibliographic Details