Methods and apparatus for recording and retrieval of optically readable data employ a recording medium (100) which comprises an optically active material (108) able to induce a change in properties of the medium in the presence of optical radiation having a first characteristic, such as a first optical frequency, and wherein the change in properties can be inhibited by optical radiation having a second characteristic, such as a second optical frequency. During recording, a region of the recording medium (100) is irradiated with a first beam (506) of optical radiation having the first characteristic, the beam having a sufficient intensity within a central portion of the irradiated region and being of sufficient duration to cause an optically induced change in properties of the recording medium. Simultaneously, the region of the recording medium (100) is irradiated with a second beam (508) of optical radiation having the second characteristic, the second beam having a local intensity minimum within the central portion of the irradiated region, and a local intensity maximum in at least one portion of the irradiated region adjacent to the central portion which is sufficient to inhibit the optically induced change in properties of the recording medium. A similar method is employed for retrieval, however the intensity of the first beam (506) is reduced to prevent changes in material properties within the recording medium (100).

An optical device includes a liquid crystal shutter using a first liquid crystal material, the liquid crystal shutter controlling application of a light beam to a predetermined point, corresponding to a driving waveform supplied to the liquid crystal shutter; a spatial optical modulator using a second liquid crystal material whose contrast becomes a maximal contrast at a temperature different from that of the first liquid crystal material, the spatial optical modulator modulating the light beam corresponding to a driving waveform supplied to the spatial optical modulator; and a supplying unit that supplies to the liquid crystal shutter and the spatial optical modulator, driving waveforms that are adjusted such that the contrasts of the liquid crystal shutter and the spatial optical modulator each become equal to or greater than 50% of the maximal contrast at a same temperature,

An information verification method and related device are provided. In the method, a fluorescent signal may be obtained, where the fluorescent signal is an electrical signal generated based on a plurality of fluorescent spots, and the fluorescent signal includes a plurality of pulse signals; an information symbol corresponding to each pulse signal may be determined based on a preset amplitude threshold and an amplitude of each pulse signal; an information sequence may be obtained based on the information symbol corresponding to each pulse signal; and a verification result of the information sequence may be obtained based on a first quantity of pulse signals between any two pulse signals in the plurality of pulse signals and a time interval between the any two pulse signals. According to the application, resulting in an error in information content corresponding to the read signal can be resolved.