Fast Photodiode Optical Detector

Products

		Compare	Model	Compatibility	sortOrder	rankScore	ranking	Drawings, CAD & Specs		Sensor Type	Rise Time/Fall Time	Spectral Range	Active Area Diameter	Maximum Average Power	Availability	Featured Item	Price		Brand
		7Z02509 FPD-IG-175 High Speed Optical Detector, InGaAs, 0.175 ns, Ø0.1 mm, 900-1700 nm $611 Show	7Z02509 FPD-IG-175 High Speed Optical Detector, InGaAs, 0.175 ns, Ø0.1 mm, 900-1700 nm	UNIVERSAL	0.0	1.0	0.0		0.0	InGaAs	175 ps	900-1700 nm	0.1 mm	10 mW	Show		$611		Ophir

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Specifications

Product Name

FPD-IG-175
Sensor Type

InGaAs
Rise Time/Fall Time

<175 ps
Spectral Range

900-1700 nm
Active Area Diameter

0.1 mm
Noise Equivalent Power

<0.03 pW/√Hz
Detector Area

0.0079 mm²
Wavelength of Peak Sensitivity

1600 nm
Responsivity at Peak Wavelength

1.1 A/W
Responsivity (Irradiance) at Peak Wavelength

4.3 x 10⁻³ V/(W/cm²)
Bias Voltage

6 VDC

Bias Voltage Source

Batteries
Bandwidth

>2 GHz
Dark Current

<2 nA
Maximum Average Power

10 mW
Mounting (Tapped Holes)

8-32 & M4
Output Connector

BNC
Accessory Thread

M20x1
Dimensions

54 x 34 x 40 mm (LxWxD)
CE Compliance

Yes
UKCA Compliance

Yes
China RoHS Compliance

Yes

Features

Pulse Characterization Sensor Overview

Using these Ophir fast photodetectors, you can see and measure the temporal characteristics of pulsed and CW laser beams.

Fast Photodiode Spectral Responsivity

Responsivity is defined as the produced photocurrent (in Amperes) per Watt of incident radiation. It is a function of wavelength. Hence, the spectral response of the photodiode should be as high as possible at the wavelength of the laser to be measured. The spectral responsivities of the FPD series are shown in the figure. Ophir offers several fast photodiodes models with Silicon photodiodes having spectral response from 320 nm to 1100 nm, UV enhanced Silicon with extended response from 193 nm to 1100 nm, and InGaAs photodiodes which are sensitive from 900 nm to 1700 nm.

Frequently Asked Questions

I need to measure the temporal pulse shape of a very powerful laser. How can I do that without damaging the detector?
Answer
There are several possible ways to do this:
- Use a beam sampling optic (partially reflective mirror or uncoated window).
- Feed the laser beam into an integrating sphere and attach the temporal detector to the sphere using the adapter accessory.
- Use a beam dump and position the detector such that it picks up some of the reflected laser radiation.
Attenuating accessories are available (see temporal detector's product page). Laser power density on the attenuators should be less than 50 W/cm².

The temporal sensor can provide accurate measurement of temporal parameters. How can I relate those to absolute value of pulse energy?
Answer
Pulse energy can be measured directly using one of Ophir's calibrated energy sensors. Another way is to use a calibrated power sensor and calculate the pulse energy using:
Pulse energy [J] = average power [W] / pulse rate [pulses per second]
Temporal sensors provide a signal that is proportional to the instantaneous power output of the laser. When viewing the pulse waveform on an oscilloscope, the integrated area under the curve is proportional to the total pulse energy.

Do I need to recalibrate my instrument?
Answer
Ophir's temporal sensors do not require calibration.

What is the difference between calibrated power sensors such as PD300 and temporal sensors?
Answer
Calibrated power sensorsmeasure the average power of CW and pulsed laser beams. The sensor is connected to an Ophir Meter or PC Interface. Power sensors are optimized for low noise and linear response in order to maximize power measurement accuracy. The measured laser beam must be smaller than the sensor's aperture in order to obtain an accurate power measurement. Temporal sensors are optimized for high speed response in order to reproduce pulse temporal characteristics with high fidelity. A temporal sensor is usually smaller than the laser beam size and samples a portion of the beam. The temporal sensor is connected to a scope or spectrum analyzer to display temporal characteristics of pulsed lasers.

I don’t see my signal on the oscilloscope or the signal is not as expected. What should I do?
Answer
See the troubleshooting section of the user manual in the temporal detector's product page for detailed information.

I sometimes need to see an analog representation of my laser power on a scope, in parallel to measuring it with a thermal sensor. What solutions are available?
Answer
There are a number of options, depending on the purpose.
- In many cases, the simplest solution could be to make use of the analog output of the meter – that gives a voltage signal proportional to the actual reading (it is in fact just a D/A translation of what is being displayed), so it represents a fully calibrated reading. The full scale value is a function of the meter being used and the power range it is on.
- The "SH to BNC connector" (Ophir P/N 7Z11010) simply takes the raw output from the detector element and sends it to the scope. It bypasses the sensor's EEROM which contains the calibration data, so it essentially turns the sensor into an uncalibrated "dumb" analog sensor. It should be noted, though, that in some cases we could be talking about a signal to the scope that may be low, perhaps even near the noise level of the scope, which limits the usefulness of this method at low powers.
- If the need is to see the pulse width – the temporal profile – the solution (assuming applicable specs) is to use an approprinte temporal sensor connected to a scope. You can point it anywhere where it will catch some backscatter from your laser, and you'll see the pulse temporal form as it really is.

In the specifications of the “Pulse Characterization Sensors”, Noise Equivalent Power is specified in units of “√Hz”. What does that mean”?
Answer
Admittedly a unit such as “√ Hz” is not very intuitive. In general: Noise Equivalent Power (NEP) is defined as the signal power that gives a signal-to-noise ratio of 1 in a one-hertz output bandwidth. Taking the bandwidth of the measurement into account is where the “square root of Hz” comes in. The noise spectrum typically has a relatively flat response, and the noise level changes with the square root of the frequency range. For example, if the frequency range doubles, the noise component increases by √2 (1.414). In detector datasheets, the bandwidth is typically normalized to 1 Hz (which is usually far below the detection bandwidth), to allow detectors with different bandwidth specifications to be directly compared.

What kind of measurements can I do with a temporal detector? Why are they important?
Answer
With a temporal detector you can measure the rise time, fall time, pulse duration and pulse frequency. Many laser applications use pulsed laser, for example medical lasers, LIDARs, and high power fiber laser for metal processing to name a few. The parameters of the laser pulses are critical for the performance of the application.

Frequently Asked Questions

I need to measure the temporal pulse shape of a very powerful laser. How can I do that without damaging the detector?
Answer
There are several possible ways to do this:
- Use a beam sampling optic (partially reflective mirror or uncoated window).
- Feed the laser beam into an integrating sphere and attach the temporal detector to the sphere using the adapter accessory.
- Use a beam dump and position the detector such that it picks up some of the reflected laser radiation.
Attenuating accessories are available (see temporal detector's product page). Laser power density on the attenuators should be less than 50 W/cm².

The temporal sensor can provide accurate measurement of temporal parameters. How can I relate those to absolute value of pulse energy?
Answer
Pulse energy can be measured directly using one of Ophir's calibrated energy sensors. Another way is to use a calibrated power sensor and calculate the pulse energy using:
Pulse energy [J] = average power [W] / pulse rate [pulses per second]
Temporal sensors provide a signal that is proportional to the instantaneous power output of the laser. When viewing the pulse waveform on an oscilloscope, the integrated area under the curve is proportional to the total pulse energy.

Do I need to recalibrate my instrument?
Answer
Ophir's temporal sensors do not require calibration.

What is the difference between calibrated power sensors such as PD300 and temporal sensors?
Answer
Calibrated power sensorsmeasure the average power of CW and pulsed laser beams. The sensor is connected to an Ophir Meter or PC Interface. Power sensors are optimized for low noise and linear response in order to maximize power measurement accuracy. The measured laser beam must be smaller than the sensor's aperture in order to obtain an accurate power measurement. Temporal sensors are optimized for high speed response in order to reproduce pulse temporal characteristics with high fidelity. A temporal sensor is usually smaller than the laser beam size and samples a portion of the beam. The temporal sensor is connected to a scope or spectrum analyzer to display temporal characteristics of pulsed lasers.

I don’t see my signal on the oscilloscope or the signal is not as expected. What should I do?
Answer
See the troubleshooting section of the user manual in the temporal detector's product page for detailed information.

I sometimes need to see an analog representation of my laser power on a scope, in parallel to measuring it with a thermal sensor. What solutions are available?
Answer
There are a number of options, depending on the purpose.
- In many cases, the simplest solution could be to make use of the analog output of the meter – that gives a voltage signal proportional to the actual reading (it is in fact just a D/A translation of what is being displayed), so it represents a fully calibrated reading. The full scale value is a function of the meter being used and the power range it is on.
- The "SH to BNC connector" (Ophir P/N 7Z11010) simply takes the raw output from the detector element and sends it to the scope. It bypasses the sensor's EEROM which contains the calibration data, so it essentially turns the sensor into an uncalibrated "dumb" analog sensor. It should be noted, though, that in some cases we could be talking about a signal to the scope that may be low, perhaps even near the noise level of the scope, which limits the usefulness of this method at low powers.
- If the need is to see the pulse width – the temporal profile – the solution (assuming applicable specs) is to use an approprinte temporal sensor connected to a scope. You can point it anywhere where it will catch some backscatter from your laser, and you'll see the pulse temporal form as it really is.

In the specifications of the “Pulse Characterization Sensors”, Noise Equivalent Power is specified in units of “√Hz”. What does that mean”?
Answer
Admittedly a unit such as “√ Hz” is not very intuitive. In general: Noise Equivalent Power (NEP) is defined as the signal power that gives a signal-to-noise ratio of 1 in a one-hertz output bandwidth. Taking the bandwidth of the measurement into account is where the “square root of Hz” comes in. The noise spectrum typically has a relatively flat response, and the noise level changes with the square root of the frequency range. For example, if the frequency range doubles, the noise component increases by √2 (1.414). In detector datasheets, the bandwidth is typically normalized to 1 Hz (which is usually far below the detection bandwidth), to allow detectors with different bandwidth specifications to be directly compared.

What kind of measurements can I do with a temporal detector? Why are they important?
Answer
With a temporal detector you can measure the rise time, fall time, pulse duration and pulse frequency. Many laser applications use pulsed laser, for example medical lasers, LIDARs, and high power fiber laser for metal processing to name a few. The parameters of the laser pulses are critical for the performance of the application.

Accessories

Attenuators

	Compare	Description	Compatibility	Drawings, CAD & Specs	Avail.	Price
		7Z08200 ND1 Attenuator, Nom. X10, FPS-1 and FPD	UNIVERSAL		Show	$279
		7Z08201 ND2 Attenuator, Nom. X50, FPS-1 and FPD	UNIVERSAL		Show	$275

FPD to IS6 Adapter

For mounting FPD sensor series (except FPS-1) to North Pole post of IS6 series.

	Compare	Description	Compatibility	Drawings, CAD & Specs	Avail.	Price
		7Z08350 FPD Sensor Adapter, IS6 Integrating Sphere, North Pole Port, Matte Black Coated	UNIVERSAL		Show	$300

Fiber Connector Adapters

These adapters allow for power measurement of connectorized fiber-optic cables. The sensor may need an additional mounting bracket to connect to these fiber adapters.

Description	Compatibility	Avail.	Price
7Z08227 SC Fiber Connector Adapter, Power and Energy Sensors	UNIVERSAL	Show	$302
7Z08226 ST Fiber Connector Adapter, Power and Energy Sensors	UNIVERSAL	Show	$264
7Z08229 FC Fiber Connector Adapter, Power and Energy Sensors	UNIVERSAL	Show	$153
1G01236A SMA Fiber Connector Adapter, Power and Energy Sensors	UNIVERSAL	Show	$74

Extended Warranty for Sensor

Customers that purchase the above items also consider the following items. Ophir-Spiricon meters and sensors include a standard manufacturers warranty for one year. Add a one year Extended Warranty to your meter or sensor, which includes one recalibration.

	Compare	Description	Compatibility	Drawings, CAD & Specs	Avail.	Price
		XWAR-SENSOR Extended Warranty for Sensor	UNIVERSAL		Contact Us	$475

Resources

InGaAs 175 ps High Speed Optical Detector with 0.1 mm Active Diameter

InGaAs 175 ps High Speed Optical Detector with 0.1 mm Active Diameter

Overview

Products

Specifications

Features

Pulse Characterization Sensor Overview

Fast Photodiode Spectral Responsivity

Frequently Asked Questions

Frequently Asked Questions

Accessories

Attenuators

FPD to IS6 Adapter

Fiber Connector Adapters

Extended Warranty for Sensor

Resources

Data Sheets

Drawings & CAD

Manuals

Catalogs

Technical Articles

Technical Notes

FPD-UV-3000 UV Silicon 3 ns High Speed Optical Detector

FPD-IG-25 InGaAs 25 ps High Speed Optical Detector

IS6-C-UV UV-Silicon 1W Collimated 5.3 in. ID Ø25mm Aperture Integrating Sphere

IS6-C-VIS Silicon 30W Collimated 5.3 in. ID Ø25mm Aperture Integrating Sphere

IS6-D Divergent Beam 5.3 in ID Ø63.5mm Aperture Integrating Sphere Body

FPD-UV-3000 UV Silicon 3 ns High Speed Optical Detector

FPD-IG-25 InGaAs 25 ps High Speed Optical Detector

IS6-C-UV UV-Silicon 1W Collimated 5.3 in. ID Ø25mm Aperture Integrating Sphere

IS6-C-VIS Silicon 30W Collimated 5.3 in. ID Ø25mm Aperture Integrating Sphere

IS6-D Divergent Beam 5.3 in ID Ø63.5mm Aperture Integrating Sphere Body

Have questions? Require assistance?

Product Comparison

InGaAs 175 ps High Speed Optical Detector with 0.1 mm Active Diameter

InGaAs 175 ps High Speed Optical Detector with 0.1 mm Active Diameter

Overview

Products

Specifications

Features

Pulse Characterization Sensor Overview

Fast Photodiode Spectral Responsivity

Frequently Asked Questions

Accessories

Attenuators

FPD to IS6 Adapter

Fiber Connector Adapters

Extended Warranty for Sensor

Resources

Data Sheets

Drawings & CAD

Manuals

Catalogs

Technical Articles

Technical Notes

Related Products

Have questions? Require assistance?