Abstract: An optical waveguide chip having an optical waveguide which can keep good transmission characteristics stably over a long period of time without separations or cracks even in severe use conditions, and an optical fiber guide portion formed without cracks firmly with a shape and a size corresponding to those of an optical fiber is provided. An optical waveguide chip 1 has a support 2, an optical waveguide 3 having a core portion 7, clad layers 6 and 8, an optical fiber guide portion 4 for positioning an optical fiber to be connected with the optical waveguide 3, and a cover member (glass plate) 5. The optical waveguide 3 is made of a radiation-sensitive polysiloxane composition. The optical fiber guide portion 4 is made of the same or a different radiation-sensitive polysiloxane composition as/from the material of the optical waveguide 3. The optical waveguide 3 and the optical fiber guide portion 4 are formed by separate processes.

Abstract: A process for preparing poly-.alpha.-amino acid particles comprising polymerizing an .alpha.-amino acid-N-carboxy anhydride using a polymerization initiator in an organic solvent in which both the solubility of the .alpha.-amino acid-N-carboxy anhydride and the solubility of the produced poly-.alpha.-amino acid are 0.1 g/100 ml or less at 25.degree. C. Polyamino acid particles having a high molecular weight and a small bulk specific gravity can be manufactured very easily without requiring specific procedures. The polyamino acid particles can be used as a coating material for papers, resins, rubbers, and fibers; particles for cosmetics; particles for diagnostic drugs; fillers for chromatography; and an encapsulating material for drugs, fertilizers, and perfumes.