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Universal Optical Power Meter Laser
-Beam Char
acterization
Photodiodes
, Integr
ating Spher
es & Amplifier
s
P
ower & Ener
gy Meter
s
50.4
1
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The Melles Griot universal optical power meter, an easy-to-
use instrument, consists of a controller, a detector, and a range
of accessories.
$
High-sensitivity power measurements for free-space and
fiber-optic beam-delivery systems
$
Measurements from a few pW to 2 W with an attenuating
filter and appropriate detector
$
NIST traceable accuracy of 83%
$
Visible, near-infrared, and telecommunications wavelengths
measured with the appropriate detectors
$
Accessories available for ST, SC, FC, SMA connectors, bare
fiber, and 2.5-mm fiber ferrule.
CONTROLLER/DISPLAY
$
The power meter measures average, true rms, ac rms,
peak-to-peak, and peak power.
$
Measurements displayed in watts, dB-m, or detector current.
$
The menu-driven front panel simplifies use.
$
IEEE option allows for incorporation into automated test
and data acquisition systems.
$
Analog output is included for use with oscilloscopes,
chart recorders, and A/D converters.
SILICON AND GERMANIUM DETECTOR OPTIONS
$
Each detector head is spectrally calibrated with calibration
data stored in a unique memory module within the detector
head.
$
An attenuation filter, whose spectral response is held within
the memory, is supplied with each detector head.
$
For measuring the power of laser-line generators and
divergent, inhomogeneous, or large beam sources,
Melles Griot offers a choice of integrating spheres
calibrated from 400 nm to 1800 nm with either a silicon
or germanium detector head.
SPECIFICATIONS:
UNIVERSAL OPTICAL POWER METER CONTROLLER
Display Resolution: 4 digits
Range: 8 decades, TIA gains of 10
3
10
10
V/A
Bandwidth: 50 kHz max30 Hz min, range dependent
Zero drift: 80.1% of full scale
Displays:
Digital: LCD, 64!192 pixel
Analog: Precision backlit mirror scale
Analog Output:
81 V max; transfer function displayed on LCD
Power Requirements:
Voltage:
115 Vac +10%, 420%, 230 Vac 810%,
rear-panel selector switch
Frequency: 5060 Hz
Dimensions (W!H!D):
191 mm !133 mm!108 mm (7.5 in.!5.3 in.!4.3 in.)
Weight: 2.5 kg (5.5 lb)
Temperature
+15º to +35ºC (operating)
520º to +50ºC (storage)
Safety: CE compliant
Universal Optical
Power Meter
Universal optical power meter controller
HOW TO ORDER
To order a universal optical power meter, select the
13 PDC 001 controller. Append suffix /IEEE for the
IEEE 488.2 interface option. Select required detector,
stand or mount, and fiber adaptors from the options
shown on page 50.7.
Available in: Production Quantities Custom Configurations
Chpt. 50 Final 8/27/99 2:40 PM Page 50.4 Laser
-Beam Char
acterization
Photodiodes
,
Integr
ating Spher
es & Amplifier
s
P
ower & Ener
gy Meter
s
13 PDC 001,
13 PDC 001/IEEE
152 mm integrating
sphere with detector
13 PDH 003 (Si)
67 mm integrating
sphere with detector
13 PDH 005 (Si) or
13 PDH 105 (Ge)
detector heads
13 PDH 001 (Si) or
13 PDH 101 (Ge)
Universal Optical Power Meter
METER ZERO
SETUP
RANGE
SELECT
NULL
POWER
ON
stand
13 PDA 015
adjustable mount
07 PBS 003
adjustable mount
07 PBS 003
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1
50.5
Detector options for the universal optical power meter
LASER BEAM CHARACTERIZATION
For information on a wide variety of instruments that
measure beam width, intensity profile, pointing
stability, and other parameters, see Chapter 48,
Laser Beam Characterization.
PHOTODIODES
INTEGRATING SPHERES, AND AMPLIFIERS
For information on the complete Melles Griot line of
photodiodes and high-frequency, wide-bandwidth,
and large-dynamic-range amplifiers, see Chapter 49,
Photodiodes, Integrating Spheres, and Amplifiers.
Chpt. 50 Final 8/27/99 2:40 PM Page 50.5 Laser
-Beam Char
acterization
Photodiodes
, Integr
ating Spher
es & Amplifier
s
P
ower & Ener
gy Meter
s
Power Meter Accessories
ST Connector Adaptor
SC Connector Adaptor
FC Connector Adaptor
SMA Connector Adaptor
Bare-Fiber Connector Adaptor
2.5-mm Ferrule Adaptor
50.6
1
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Universal Optical Power Meter Controllers
Detectors for Universal Optical Power Meter
PRODUCT NUMBER
Without IEEE Interface
With IEEE Interface
13 PDC 001
13 PDC 001/IEEE
Detector Options
1
Wavelength (nm)
Power
NEP
2
Accuracy
3
(%)
PRODUCT NUMBER
Silicon
Detector Head Only
(10-mm clear aperture)
152-mm Integrating
Sphere and Detector
67-mm Integrating
Sphere and Detector
4001100
4001100
4001100
@ 630 nm
5 pW1 mW
5 nW2 W
(with attenuator)
2 nW 400 mW
250 pW50 mW
5 pW
5 nW
(with attenuator)
2 nW
250 pW
8
3
8
5
(with attenuator)
8
10
8
10
13 PDH 001
13 PDH 003
13 PDH 005
Germanium
Detector Head
(4.8-mm clear aperture)
67-mm Integrating
Sphere and Detector
8001800
8001800
@ 1500 nm
10 nW1 mW
10 mW200 mW
(with attenuator)
500 nW50 mW
10 nW
10 mW
(with attenuator)
500 nW
8
5
8
10
(with attenuator)
8
10
13 PDH 101
13 PDH 105
1
All detectors have an integrated cable 1.5 m long.
2
Specified at peak response.
3
1% of reading or full scale, whichever is greater.
*Compatible with detector heads 13PDH 001, 005, 101, 105. Requires 13 PDA 013 for use
with 13 PDH 003.
PRODUCT NUMBER
13 PDA 001
13 PDA 003
13 PDA 005
13 PDA 007
13 PDA 009
13 PDA 011
PRODUCT NUMBER
Note: A controller system comprises, at a minimum , a controller, detector, and stand.
Fiber Adaptors*
Power Meter Accessories
Fiber Adaptor Interface for 152-mm Integrating Sphere
Stand for Either Silicon or Germanium Detector Heads
Adjustable Mount for Either 67 or 152-mm
Integrating Sphere (inch/metric)
Universal Base Plates (inch/metric)
13 PDA 013
13 PDA 015
07 PBS 003 / 07 PBS 503
07 BPS 003 / 07 BPS 503
Chpt. 50 Final 8/27/99 2:40 PM Page 50.6 Laser
-Beam Char
acterization
Photodiodes
,
Integr
ating Spher
es & Amplifier
s
P
ower & Ener
gy Meter
s
In many photodetector applications it is necessary to measure the absolute or relative intensity of a divergent source
or an inhomogeneous beam that is much larger than the active area of a photodetector. In those situations,
integrating spheres are used to scramble or average light by multiple diffuse reflections in order to obtain meaningful
intensity measurements. An integrating sphere is a hollow sphere (often aluminum) whose entire inner surface is
uniformly coated with a layer of material that has a high diffuse reflectance.
When light from a source enters an integrating sphere, it loses all memory of direction and polarization. At the exit
port, the light intensity is uniform and diffuse. Although other methods have been developed to deal with the
problems of averaging the intensity of an inhomogeneous source or of a wide-angle beam, an integrating sphere is the
best solution in many applications. In fact, the only real differences between the integrating spheres of today and the
spheres of many years ago are the improved quality and stability of the diffuse reflective coatings.
PERFORMANCE CHARACTERISTICS
Throughput and stability are two meaningful figures of merit for integrating spheres. Throughput is defined as the
ratio of the flux exiting the sphere to the flux entering the sphere. It is determined by the size of the input and exit
ports relative to the sphere area and by the reflectivity:
where A
e
is the area of the exit port divided by the total sphere area
R is the reflectance of the coating
A
p
is the total area of all ports divided by total sphere area.
Stability is the reciprocal of the change in throughput with respect to the change in reflectivity of the coating. This is
an important parameter since, in certain operating environments, the reflectivity of the coating may degrade slightly
over a long period of time and the degradation may be nonuniform over the sphere surface. A small change in the
reflectivity of a low-stability sphere will result in a large change in throughput. Therefore, a low-stability sphere is less
likely to give an accurate, reproducible reading than a high-stability sphere. Stability is related to throughput. A high-
throughput sphere is inherently less stable than a lower throughput sphere because of the nonlinear dependence of
throughput on reflectivity.
Stable spheres have reflectivity values of 90% or less, whereas low-stability (high-throughput) spheres typically have
reflectivities of 79% or higher. For example, a typical low-throughput sphere with a 90% reflectivity coating will have
an inherent stability of 0.5, whereas an identical high-throughput sphere with a 99% reflectivity coating will have a
stability factor of 0.05.
Integrating spheres are available as components in Chapter 49, Photodiodes, Integrating Spheres, and Amplifiers.
FUNDAMENTALS OF INTEGRATING SPHERES
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1
50.7
Throughput
A R
1 R 1 A
e
p
=
(
)
[
]
4
4
Chpt. 50 Final 8/27/99 2:40 PM Page 50.7