Abstract

A solar magnetograph employing as detectors a pair of self-scanning 512-element integrated diode arrays is described. Coupled to a 1.5-m telescope, photospheric flux as small as 5(10⁶) maxwells is detected, corresponding in intensity to ΔI/I = 3(10⁻⁴) at λ0.8688 μm. Measured photometric properties of the diode array are given, including MTF as a function of wavelength, dark current as a function of temperature, completeness of readout, optical and electronic fixed-pattern noise. An integrating preamplifier is presented that achieves a measured noise, when connected to the array, equivalent to 950 electrons at the input for a bandwidth of 3(10⁵) Hz. These data provide a basis for an evaluation of the detector performance at low light levels beyond the needs of the magnetograph. Operated at near liquid nitrogen temperature, the noise and cooling characteristics indicate the detector has promise as a low light level sensor.

© 1976 Optical Society of America

Kitt Peak 60-cm vacuum telescope

W. C. Livingston, J. Harvey, A. K. Pierce, D. Schrage, B. Gillespie, J. Simmons, and C. Slaughter
Appl. Opt. 15(1) 33-39 (1976)

The Solar Magnetograph of the High Altitude Observatory

R. H. Lee, D. M. Rust, and H. Zirin
Appl. Opt. 4(9) 1081-1084 (1965)

Performance of a silicon vidicon at low signal levels

Donald M. Hunten and C. J. Stump
Appl. Opt. 15(12) 3105-3110 (1976)

Photoelectron counting with an image intensifier tube and a self-scanned photodiode array

Bill R. Sandel and A. Lyle Broadfoot
Appl. Opt. 15(12) 3111-3114 (1976)

Self-scanned photodiode array: high performance operation in high dispersion astronomical spectrophotometry

Steven S. Vogt, Robert G. Tull, and Phillip Kelton
Appl. Opt. 17(4) 574-592 (1978)