Catalog & Manuals
What does the PD300 "Background Subtraction" do?
Ophir's Photodiode PD300 and PD300-1W sensors offer automatic background subtraction so the measurement is not sensitive to room light. With "filter out" (i.e. the external filter removed for low light measurements), 2 separate detector elements are visible. The beam to be measured is incident only on the outer of the 2 detectors, but background light reaches both detectors. The instrument will show the power measured by the outer detector minus that measured by the inner detector.This patented method cancels out 95% - 98% of background light under normal room conditions, even if it is constantly changing.Close
How do I take off the removable filter from the PD300?
Can I use a sensor from the PD300 family to measure average power of pulsed lasers?
In general yes, but several technical issues need to be kept in mind (most of which are results of the fast physical response time of these sensors):
- The pulse rate should be more than about 30Hz, otherwise the reading is unstable. At higher pulse frequencies, the sensor will respond as if the beam were CW.
- It is possible for a pulsed beam to have average power within the sensor spec and yet have the energy of the pulses themselves be high enough to cause a momentary saturation of the sensor. It is important to be sure that pulse energy is also within sensor spec (the parameter "Max pulse energy" is included in all specs for the PD300 family, for just this reason).
- The beam diameter should be no less than about 1mm .
- The average power and power density restriction in the spec should not be exceeded
Note: At the maximum pulse energy limit given in the spec, the reading will be saturated by about 5%, i.e. the reading will be about 5% lower than it should be. At 1/3 the maximum, the saturation will be about 1%.Close
Can a lost PD300 filter be replaced?
Technically it could be replaced, but it is not just a matter of replacing the filter. Since the PD300 is a "calibrated" sensor it requires that the filter also be "calibrated". Especially since the PD300 response varies with wavelength, it requires that both the PD300 and the filter be calibrated over the entire spectral range with a monochromator. Because of the cost to calibrate the replacement filter with the PD300 sensor, we recommend purchasing a new PD300 sensor when a replacement filter is needed.Close
The total error when using a PD-300 head is listed as +/- 3%. Is that 3% of the reading or 3% of the total range?
When using a photodiode laser power sensor to measure very low power pulsed beams (nW to mW), there are some issues you need to be aware of. This video shows you how to avoid some common problems and ensure maximum accuracy.
In this short “Basics” video we review in general how one goes about measuring laser beam power, so that you’ll have a clear basic understanding of what the different sensor types are, and when you would use which type.
Are you measuring a laser beam coming at an angle correctly?
Ever wonder how your laser power measurements are affected by your beam’s angle of incidence?
In this video, you will learn to what degree a beam’s incidence angle matters, and for which sensor types this should be taken into account.
In this short “Basics” video, we review in general the use of photodiode sensors for measuring very low laser powers.
Laser Power Sensors introduction
As described in the general introduction, the thermopile sensor has a series of bimetallic junctions. A temperature difference between any two junctions causes a voltage to be formed between the two junctions. Since the junctions are in series and the «hot» junctions are always on the inner, hotter side, and the «cold» junctions are on the outer, cooler side, radial heat flow on the disc causes a voltage proportional to the power input. Laser power impinges on the center of the thermopile sensor disk (on the reverse side of the thermopile), flows radially and is cooled on the periphery. The array of thermocouples measures the temperature gradient, which is proportional to the incident or absorbed power. In principle, the reading is not dependent on the ambient temperature since only the temperature difference affects the voltage generated and the voltage difference depends only on the heat flow, not on the ambient temperature. 阅读更多...
Common Reasons for Photodiode Sensor Damage or Out of Tolerance Conditions
We have included this document with your recent calibration order because we have noticed an out of tolerance condition obtained from your equipment when returned for calibration. This document was created to assist our valued customers in the proper care and maintenance of Ophir photodiode sensors. The following information is for reference only. If you have any reason to believe that the sensor is no longer performing within the original specifications, we always recommend that you send it in for repair and/or recalibration by our trained technicians to bring the unit back to the proper NIST traceable standards.
Ophir photodiode sensors can be used for many years without any repairs when used with the proper laser optical setup. Many of our customers have sensors that are using their original absorber that are over ten years of age. We hope that this document will enable you to also enjoy the long life and reliable results that Ophir- Spiricon is known for. 阅读更多...
How to Properly Select a Laser Power or Energy Sensor
The selection of a sensor to accurately measure the power of a laser or energy of a pulsed laser can seem like a simple and easy procedure. However, many times the selection process is limited to choosing a sensor that only meets the range of power or energy to be measured, leaving out several other essential criteria of the laser specifications; that without their consideration, can allow the wrong sensor to be selected, the laser to be measured inaccurately and likely to cause the sensor to fail prematurely.阅读更多...
Ophir Power/Energy Meter Calibration Procedure and Traceability/Error Analysis
This document discusses the interpretation and basis for stated measurement accuracy of Ophir Laser Power/Energy meters.
1. General Discussion
2. Combination of Errors and Total Error
3. Analysis of Power and Energy Calibration Errors
4. Detailed Analysis of Power and Energy Calibration Errors
Laser Measurements in Materials Processing: How and When They Absolutely, Positively Must Be Made
How do I know what range, or scale, to set my power/energy meter to? And what happens if I go over range?
Each given range represents one level of gain of an internal amplifier. The electronics, as always, have a limited Dynamic Range. If the measured signal is too low, in other words near the bottom of the range, then it may be lost in the noise and the reading will be inaccurate and noisy. If it’s too high – there may be saturation issues. To give an instrument a usefully wide dynamic range, multiple scales or ranges are used. Switching from range to range can be automatic (“Autorange”), or manual. Autoranging simply starts automatically at the least sensitive range and works its way down the ranges, sampling the signal as it goes, till it finds a range at which the signal is properly detected. Note, by the way, that only in POWER mode is Autoranging available. If we are working in Single Shot Energy mode, there is no Autoranging – simply because when we are measuring a single pulse, the instrument has no opportunity to work its way down the ranges as in Power mode. 阅读更多...
White Paper – Low Frequency Power Mode
Types of power / Energy Laser Sensors General Introduction
Power and Single Shot Energy Sensors
Ophir provides two types of power sensors: Photodiode sensors and Thermal sensors. Photodiode sensors are used for low powers from picowatts up to hundreds of milliwatts and as high as 3W. Thermal sensors are for use from fractions of a milliwatt up to thousands of watts.
Thermal sensors can also measure single shot energy at pulse rates not exceeding one pulse every ~5s.
Repetitive Pulse Energy Sensors
For higher pulse rates, Ophir has pyroelectric energy sensors able to measure pulse rates up to tens of KHz. These are described in the energy sensor section, section 1.3.
Measuring Average Power of Pulsed Lasers with Photodiodes
5 Situations Where Laser Performance Measurement is Necessary
- Ø35 W x 24 D (mm)
- 0.2 s
- CE, UKCA, China RoHS
7Z08227This fiber adapter is used for connecting power and energy sensors to a standard SC-type fiber. Many sensors need an additional mounting bracket to connect to all fiber adapters. More information can be found in the datasheet below.
7Z08226This fiber adapter is used for connecting power and energy sensors to a standard ST-type fiber. Many sensors need an additional mounting bracket to connect to all fiber adapters. More information can be found in the datasheet below.
7Z08229This fiber adapter is used for connecting power and energy sensors to a standard FC-type fiber. Many sensors need an additional mounting bracket to connect to all fiber adapters. More information can be found in the datasheet below.
1G01236AThis fiber adapter is used for connecting power and energy sensors to a standard SMA-type fiber. Many sensors need an additional mounting bracket to connect to all fiber adapters. More information can be found in the datasheet below.
1G02259A mounting bracket is needed to connect round photodiode sensors to a fiber adapter (SC, ST, FC or SMA). This bracket can be used for the PD300R (round) photodiode series, as well as the FPS-1 fast photodiode. It is not needed for the PD300-IRG sensor. This bracket is also used for mounting ND attenuators on the FPS-1.
For mounting to SM1 optical components and systems
5m cable to connect sensor to power meter or interface. Order along with sensor to receive this instead of the standard 1.5m cable.
10m cable to connect sensor to power meter or interface. Order along with sensor to receive this instead of the standard 1.5m cable.