attoPUBLICATIONS attoCATALOG-2015/16 | Page 68

attoDRY800 PAGE 66 attoDRY800 Optical Cryo-Microscope integrated apochromatic low temperature optics for maximum collection efficiency vacuum shroud with 5 optical windows When collecting small optical signals, e.g. from single photon emitters, which constitute promising candidates for solidstate based qubits, it is a crucial requirement to maximize the collection efficiency. This is best done with objectives that feature high numerical apertures, which usually implies a low working distance. In this case getting the objective close to the specimen is necessary. Most high quality optics are designed for room temperature use, which would not survive periodic thermal cycling. Putting an objective out­s ide of a cryostat often results in large drifts, which are inacceptable for the long measurement cycles required when focusing on a single quantum emitter. The solution is provided by the attoDRY800 optical cryo-microscope: based on the unique low vibration design of the attoDRY800 cryo-opti­ cal table, it features a fully integrated cold objective, hence minimizing drift while maximizing the collection efficiency. The apochromatic objective is located in cryogenic vacuum in close proximity to the