A divalent metal stannate product having a loss on ignition of 2-17% by weight, e. A reflectivity of the recording layer is specified to be more than 10%. The lamp further comprises a vertical metallic post, the post being grounded to the metallic lamp body at the post’s bottom surface. In an inner circumferential portion of the hologram, a grating is formed. The patterning device may be excited with an alternating acceleration.