Physics – Optics
Scientific paper
Jan 1990
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1990phdt........87s&link_type=abstract
Thesis (PH.D.)--UNIVERSITY OF COLORADO AT BOULDER, 1990.Source: Dissertation Abstracts International, Volume: 51-06, Section: B,
Physics
Optics
Bolometer
Scientific paper
Several bolometers were constructed for low level laser power measurement using silicon-on-sapphire (SOS) thermistors as the temperature sensors. Silicon was etched to the desired dimensions and doped heavily with phosphorous by ion-implantation to obtain the optimum values of resistance and temperature coefficient of resistance at liquid helium (LHe) temperatures. An important design feature in these bolometers was that the current noise was reduced by a considerable fraction by "burying" the conducting region below the Si-SiO_2 interface. Double implant was used in the contact region to keep the peak impurity concentration and the resulting crystalline damage level lower in order to reduce the contact noise arising from crystal defects. Satisfactory values were obtained for the optical responsivities and the noise equivalent powers. Optical NEP's of the order of 10^ {-12} w/sqrt{rm Hz} and optical responsivities of the order of 10^5 v/w were measured in our laboratory. Non-uniform doping profile used to "bury" the doped layers into the semiconductor at LHe temperatures also reduced the responsivity values and consequently increased the NEP values. Measured noise followed the expected I^2 dependence. Large signal responsivity equation (DC) was developed to supplement the existing small signal theory of bolometer performance. Window optics was modified to get polarization independence as well as to eliminate interference from multiple reflections, thereby facilitating the precision calibration of the bolometer. Electrical self-calibration was achieved for DC signals. Progress in the AC calibration method remained limited by the poor frequency response, complexity of the heat transfer mechanism and the waveform distortion of the electrical output produced by the nonlinear optical response of the bolometers.
No associations
LandOfFree
Sos Cryogenic Bolometer: Analysis, Development and Self-Calibration does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Sos Cryogenic Bolometer: Analysis, Development and Self-Calibration, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sos Cryogenic Bolometer: Analysis, Development and Self-Calibration will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1564797