Arizona Readout Test Stand (ARTS)

    ARTS is a dynamic test stand for two-photon data storage read out system. The system’s scheme is in Fig 1 below. It is based on a kinematic rail system developed by our group [T.D.Milster etc , SPIE Annual Meeting, Aug. 2 2001, San Diego, “ Semi-kinematic rails for construction of optical test stands”.] . Opto-mechanically, it consists of 4 inch x 4 inch stages and V-groove stages aligned along a fixed alignment bar, whose position is well-known. The diode laser at wavelength 638 nm and two alignment mirrors are placed in the first two 4 inch x 4 inch stages. The laser beam is then reflected 90 degrees by a dichroic beamplate, which is placed on the third 4 inch x 4 inch stage along with a high-pass (650 nm cutoff wavelength) filter. This laser beam is then delivered through a relay telescope, also positioned with the help of the kinematic V-groove system to a Geltech lens mounted on a Sony actuator. The beam is then focused into a optical disk mounted on a miniature tip-tilt-x-y stage. The dichroic beam plate combined with a high pass filter is used to separate the reflected laser beam and the fluorescent beam. A flip mirror is used to direct the fluorescent beam to two different paths. In the 1^st path, the fluorescent beam is focused into a black and white CCD camera. In the 2^nd path, a lens is used to focus the fluorescence into a knife edge prism which splits the beam into two parts A and B. Two PMTs mounted on a x-y-z stage  are used to collect two parts of this fluorescent beam. The signals’ CNR from the A+B PMT signal will be measured.

Fig 1.