THORLABS BC106-VIS User Manual

© 2011 Thorlabs
138 Thorlabs Beam 4.0
6.3
Raw Data Measurements
Beam Width (4 )
Width on X and Y axes (centroids), based on the second moment calculation
IntensitySum
yxpxx
d
centroid
xx
_
),(*)(
*4*4
2
IntensitySum
yxpyy
d
centroid
yy
_
),(*)(
*4*4
2
Beam width (4 ) can be calculated also based using radial distance (pixel -
centroid; R).
According to ISO11146-1, if the ellipticity is larger than 0.87, the beam profile
may be considered to be of circular symmetry at that measuring location. In this
case, ISO11146-1 allows to calculate only one common 4 beam width (4
simplified).
Beam Diameter (4 )
Diameter based on second moment calculation on radial distance (pixel-centroid):
IntensitySum
yxpyyxx
d
centroidcentroid
_
),(*))()((
*2*2
22
Effective Beam Diameter
Circle diameter of equivalent beam area with pixel intensities above a level X% (clip level)
down from the peak intensity:
pix
ef f
AN
D
**4
with
N number of pixels with intensities above clip level
A
pix
pixel size (for BC106 = 6.45*6.45µm²)
Peak Position
X, Y: position of the pixel with highest intensity (AD value) which is found first with
respect to reference position.
R =
22
YX
= radial distance of same pixel from reference position
Reference position is the sensor's center.
Centroid Position
X, Y and R position (first moment), calculated over all pixels with respect to the
above reference position.
140

THORLABS BC106-VIS Specifications

General

Brand	THORLABS
Model	BC106-VIS
Category	Lighting Equipment
Language	English