Abstract: An example electronic device is provided, including a housing, a lens cover, and a lens assembly disposed in the housing. The lens assembly includes a plurality of lenses sequentially arranged from an object side to an image side along an optical axis. The lens assembly satisfies a conditional expression: 0.7<IH/(4*F #)<6, where IH is a total image height of the lens assembly, and F # is an F-number of the lens assembly. At least one lens that is in the lens assembly and that is close to the object side is configured to move along the optical axis. An equivalent focal length of the lens assembly is between 18 mm and 30 mm.

Abstract: An example electronic device is provided, including a housing, a lens cover, and a lens assembly disposed in the housing. The lens assembly includes a plurality of lenses sequentially arranged from an object side to an image side along an optical axis. The lens assembly satisfies a conditional expression: 0.7<IH/(4*F #)<6, where IH is a total image height of the lens assembly, and F # is an F-number of the lens assembly. At least one lens that is in the lens assembly and that is close to the object side is configured to move along the optical axis. An equivalent focal length of the lens assembly is between 18 mm and 30 mm.

Abstract: An example optical lens includes at least seven lenses that are arranged from an object side to an image side, where in a direction from the object side to the image side, a first lens has a positive optical power, an object side surface that is of the first lens and that is near an optical axis is a convex surface, an image side surface that is of the first lens and that is near the optical axis is a concave surface, and a last lens has a negative focal power; and a back focal length BFL of the optical lens satisfies: BFL?2.5 mm.

Abstract: A gas laser, including: a semiconductor laser, an optical beam-shaping system, a pair of electrodes, a discharge tube, a rear mirror, and an output mirror. The pair of electrodes includes two electrodes. The electrodes are symmetrically disposed at an outer layer of the discharge tube in parallel. The electrodes are connected to a radio-frequency power supply via a matching network, and the electrodes operate to modify working gas in the discharge tube through radio-frequency discharge. The rear mirror and the output mirror are disposed at two end surfaces of the discharge tube, respectively. The rear mirror, taken together with the output mirror and the discharge tube, form a resonant cavity. The output mirror is configured to output a laser beam.

Abstract: A gas laser, including: a semiconductor laser, an optical beam-shaping system, a pair of electrodes, a discharge tube, a rear mirror, and an output mirror. The pair of electrodes includes two electrodes. The electrodes are symmetrically disposed at an outer layer of the discharge tube in parallel. The electrodes are connected to a radio-frequency power supply via a matching network, and the electrodes operate to modify working gas in the discharge tube through radio-frequency discharge. The rear mirror and the output mirror are disposed at two end surfaces of the discharge tube, respectively. The rear mirror, taken together with the output mirror and the discharge tube, form a resonant cavity. The output mirror is configured to output a laser beam.