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new extremely pure laser

Series G PDM
Series G Unamplified
Single Photodetectors
for light levels
of 0.1 mW and higher

Series F PDM
Series F Amplified Single Photodetectors
with new improved amplifiers
for light levels down to nanowatts and below

Series F Differential PDM
Series J Amplified
 Differential Photodetectors

like Series F single detectors,
but only the difference is amplified

New Series F Power Supply with A-B switch
Power Supply
for DC coupled PDMs
and all Differentials

International Orders
International Order Policies



Martin, Froeschner & Associates

Series J Differential Photodetector Modules

Newly Revised Amplifier Options

Even Higher Gain with Four Stages of Amplification in the same Compact Module Size

Bandwidths to 12 GHz
Sensitivities to over thirty million V/W
And a new Ultra-Low Noise Series with Noise Figures as low as 0.9 dB

Faster, more compact, and cheaper than our Award Winning Series 99 Photodetectors.

On This Page:

General Description
    Amplifier Specifications
         Same As Series F
Series J Summary & Prices
How to Order


Mod11A DOR full

Series J Mod 555A Amplified Differential Photodetector Module

General Description

A new line of inexpensive and compact fiber-coupled photodiode modules simplify capturing fast transient light signals for analysis. These devices are intended to approximate as closely as possible, a length of fiber optic cable that can be connected directly onto the input jacks of your oscilloscope or other electronic data acquisition device. Conversion of the optical signal to electronic current and voltage occurs at the last possible moment, within a mm or so of the input jacks of your scope. Co-ax cable and the problems of reflections, termination loads, phase distortion and so forth are totally eliminated. The devices are extremely compact and rugged, taking up about as much room as a typical BNC terminator

M,F&A's continuously improved Amplified Differential Photodetector Modules allow detection of the difference between two optical signals at bandwidths up to 12 GHz and overall optical conversion gains of up to one million volts/watt or more. They are perfectly suited for detection of the phase difference between two otherwise identical signals such as in range finding or in phase encoded communication protocols. Other applications include the detection of small optical modulations on a high power or unpredictably variable background.

In these modules the signal differencing is done at the optical input stage, before amplification, where the two photodiodes are arranged in a “totem-pole” configuration, as in TTL logic circuits.  The amplifier input is taken from the node between the two photodiodes, so the amplifier sees only the difference between the two photodiode currents. 

These modules are available with the same broad range of photodiode and amplifier choices as our
Series F Single Photodetector Modules.  Please skip to that page for details and specifications.

The two photodiodes are normally matched in Responsivity to within 3%.  Tighter match tolerance is available at a nominal surcharge.  Please inquire for specifics and to discuss your exact needs.

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Series J Amplified Differential Photodetector Modules
 Summary and Prices

Input Optical Connector:

    2.5mm ceramic ferrule


    UPC (compatible with flat, PC,
            and SPC)
    APC 8 degrees
    other ______________

Optical Cable:

    9/125 µm
    50/125 µm
    62.5/125 µm


    0.9mm buffer only
    3mm Kevlar and Polymer over
           0.9mm buffer
    other ______________


    1 meter (standard)

Light-Collection Optics:

    6mm fixed aspheric ($225)
    alignable Micro-Rail and "C"
          thread  compatible ($695)
    Large Aperture (inquire)

Photodiodes (matched pair):

GaAs, 450-870nm,
                  10 GHz ($2,095)

InGaAs-1, 850-1700nm,
                  3.5 GHz ($1,695)

InGaAs-2, 850-1700nm,
              >7.5 GHz ($1,995)

InGaAs-3, 950-1650nm,
                     >10 GHz ($1,995)

Amplifier Options:

True DC Coupling, with Offset Null

·                   Mod 5D, 0 to 12 GHz, 200 ohms ($675)

·                   Mod 8D, 0 to 7 GHz, 300 ohms ($675)

·                   Mod 4D, 0 to 2.8GHz, 2,500 ohms ($775


High Performance, AC Coupled

·                   Mod 5A, 12 GHz, 200 ohms ($375)

·                   Mod 55A, 8.4 GHz, 750 ohms($550)

·                   Mod 555A, 7 GHz, 2,700 ohms ($725)

·                   Mod 5555A,.5.9 GHz, 10,800 ohms ($900)

Low Noise, High Gain, AC Coupled

·                   Mod 4A, 2.8 GHz, 2,500 ohms ($375)

·                   Mod 42A, 2.8 GHZ, 7,500 ohms ($550)

·                   Mod 442A, 2 GHz, 200,000 ohms($725)

·                   Mod 444A, 1.8 GHz, 1,600,000 ohms ($725)

Lower Noise, Higher Gain, AC Coupled

·                   Mod 9A, 5 GHz, 600 ohms ($475)

·                   Mod 99A, 3.5 GHz, 7,400 ohms ($650)

·                   Mod 999A, 2.9 GHz, 90,000 ohms ($825)

·                   Mod 9999A, 2.5 GHz, 1,100,00 ohms ($1,000)

Ultra Low Noise, Higher Gain, AC Coupled

·                   Mod 7A, 2.2 GHz, 1,500 ohms ($475)

·                   Mod 77A, 1.6 GHz, 45,000 ohms($650)

·                   Mod 777A, 1.3 GHz, 1,350,000 ohms ($825)

·                   Mod 7777A, 1.0 GHz, 40,000,000 ohms ($1,000)

Output Electronic Connector:



    male plug (as in the photo above)
    female jack

Input Coupling Option:

    capacitive, non-saturating (additional A to Model

Standard External Power Supply:

    12volt rechargeable
NiMH with EMI/RFI shielding


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How to Order

We will build your Photodetectors to your specifications. The price of your detector is simply the sum of the prices of the chosen specified options.  Email us your specifications from the list under Summary and Prices above. We will return a formal quotation to confirm your specifications and expected delivery time. Quantity discounts are available, send a Request for Quotation.

Please note that these modules contain technology at the leading edge of the state of the art. Prices and specifications are subject to change.


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Martin, Froeschner & Associates
14300 Mines Road, Livermore, California, 94550

tel: (+1) 925 989 4930
fax: (+1) 925 449 4647


 Latest update June 2016


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Contact Us:

tel: +1 925 989 4930
fax: +1 925 449 4647


Martin, Froeschner & Associates
14300 Mines Road
Livermore, California

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