A solid-state imaging element or the like capable of limiting an abrupt refractive index distribution and collecting incident light at high efficiency is provided. The encodingrecording device then records the system stream onto a recording medium. g and the down conversion filter is: SdownSup. The cradle includes a base, a first fork pending from a first side of the base, a second fork pending from a second side of the base, and a retaining device disposed on the first and second fork.