Description

The quadrant signal processor (QSP1) is a position sensing instrument designed to work with all the quadrant 12 pin TO-8 packaged devices (like AXUVPS1A, SXUVPS6 etc.) The instrument is designed to amplify photogenerated currents down to the 1 pA level, acquire data from the four quadrants, and determine the beam position illuminating the detector. The entire package is 7.62 cm diameter and fits into a Newport SB80 lens mount.

This instrument determines the beam position from a high performance amplifier subsystem in conjunction with an on-board microprocessor. It is designed to collect quadrant signals for CW illumination. The system acquires data from the quadrants, processes it, and reports the resultant position. This is achieved at a rate of approximately one sample per second.

The QSP1 design is unique and has several advantages over the other quadrant signal processors available. The detector signal normalization is performed digitally. This is unaffected by noise at low illumination levels on the detector. This means that the reported position is unaffected by wide (orders of magnitude) variations in illumination intensity. This level of stability can not be performed solely by analog means used by other quadrant processors on the market. The reported measurements in QSP1 can be collected digitally avoiding the purchase of additional data collection hardware.

The QSP1 has several built-in test programs to help in debugging the instrument operation as well as assisting-in determining the validity of the collected data.

 

Schematic of Data Processing

Front Layout of QSP1

 

 

SPECIFICATIONS (ROOM TEMPERATURE)
BOARD MATERIAL - PC BOARD	FR4
DETECTOR HEIGHT (FROM BOARD SURFACE)	6 mm
POWER SUPPLY	±15 volts
POWER DISSIPATION	< 1 WATT
scales	.1, 1, 10, 100 pA/V
signal range	0 - 4.095 V
signal resolution	12 bits centered at 2.048 volts
DATA CONNECTION	SERIAL
BANDWIDTH response	2 - 10 Hz
POPULATED BOARD THICKNESS	12 MM

Return to Main Page

---