Pigtailed Photodiodes

Specifications
Item #                    FDSP625               FDSP660                FDSP780
Fiber Specs
Wavelength Range 320 – 1000 nm     610 - 770 nm     780 - 970 nm
Fiber             Graded-Index, Multimode    Nufern 630-HP, Single    Mode Nufern 780-HP, Single Mode
Core Diameter        62.5 μm                4 μm              5 μm
Numerical Aperture NA    0.27                           0.13
Back Reflections               n.a.                            < -40 dB
Detector Specs
Detector Type                       Silicon/PIN
Active Area                              Ø0.8 mm
Peak Responsivity              0.58 A/W @ 800 nm
Dark Current †                 0.01 nA Typical, 0.5 nA Max
Terminal Capacitance †           3 pF
NEP †                                  3.1 x 10-15 W/vHz
Optical Input Power, Max          50 mW
Reverse Voltage, Max              20 V
Forward Current, Max              10 mA
Operating Temperature            5 to 70 °C
Storage Temperature             -40 to 85 °C
†) 10 V reverse bias voltage

Features
Single Mode Version for 610 - 770 and 780 - 970 nm
Multimode Version
High-Speed
Wideband Characteristics
Low Bias Voltage
Reinforced Fiber
Typical Applications
Optical Communications
High-Speed Photometry
Monitoring
Thorlabs FDSP Series Pigtailed Photodiodes are high-speed pigtailed Si PIN photodiodes designed for light detection in the visible to near infrared range. These photodiodes provide wideband characteristics at a low bias voltage, ideal for use in optical communications, high-speed photometry, and monitoring applications. The FDSP series housing is a stainless steel bushing used for active coupling of the fiber to the photodiode. The fiber is reinforced with a 900 µm loose tube outer jacket and a rubber boot, which relieves fiber bending stresses.

Two models with single mode fiber and one with multimode fiber are available:

FDSP780 Nufern 780-HP Single Mode fiber, 780 - 970 nm, core diameter 5 µm, NA 0.13
FDSP660 Nufern 630-HP, Single Mode fiber, 610 - 770 nm, core diameter 4 µm, NA 0.13
FDSP625 Graded-Index Multimode fiber, 320 - 1000 nm, core diameter 62.5 µm, NA 0.27
The single mode versions are designed for low back reflection and single mode fiber also suppresses mode interferences (also called MPI - multi path interference), an essential property for signal detection in fiber based interferometers.

Connectorization with industry standard fiber connectors is available on request.