High-Speed Photodetectors

Thorlabs' newly redesigned biased photodetectors are now available in seven models that cover the wavelength range from the UV to the mid-IR (150 nm to 2.6 µm) with improved bandwidth and NEP performance. The slim housing allows the optical detector to slip in between tight setups. Each model comes complete with a fast PIN photodiode and an internal bias battery packaged in a rugged aluminum housing. With a wide bandwidth DC-coupled output, these detectors are ideal for monitoring fast pulsed lasers as well as DC optical sources. Each DET has a Bias-T circuit that combines a high frequency AC signal with a DC signal into a single output. The direct photodiode anode current is provided on a side panel BNC. This output is easily converted to a positive voltage using a terminating resistor. When looking at high-speed signals, Thorlabs recommends using a 50Ω load resistance; for lower bandwidth applications, our variable terminator is a great time saver.

All connections and controls have been moved away from the light path, thus making the DET a more useful, easier-to-use device. The SM1 threading, SM05 threading, and #8-32 (M4) threaded stubs on the DET detector housing allow it to be mounted in a cage system, lens tube system, or on a TR series post. See the mounting options tab for more details on how to incorporate a DET series photodetector into an optical setup.

Each DET arrives with a 12 VDC Bias battery already installed. A battery is used as the voltage source because batteries are an extremely low noise source of power. The battery can be replaced with a DET1A power adapter when the detector is being used in applications where a small increase in the signal noise due to noise in the line voltage isn't a consideration or the finite lifetime of a battery is not acceptable. Please see the Specs tab or the product specifications sheet for information on the battery used in the biased photodetector. The A23 battery is the replacement battery for the current DET series of photodetector, while the T505 replaces batteries used in our older models (i.e., DET1-SI and DET2-SI). Please note that due to slight positive terminal variations from manufacturer to manufacturer, Thorlabs only recommends using an Energizer battery in our DET series of photodetectors.

Specifications
Item#          Replaces           Material            Active Area                         WavelengthRange  (nm)      Peak  Response         Rise/Fall Time (ns)        NEP (W/√Hz)      Dark Current
DET25K        DET710            GaP                 4.8 mm2 (2.2 x 2.2 mm)     150 - 550                              0.12 A/W @ 440 nm       1/140                             1.6 x 10-14            40 nA
DET10A        DET210            Si                      0.8 mm2 (Ø1.0 mm)           200 - 1100                            0.45 A/W @ 750 nm       1                                     1.9 x 10-14            0.3 nA (2 nA Max)
DET36A        DET110            Si                      13 mm2 (3.6 x 3.6 mm)     400 - 1100                             0.65 A/W @ 970 nm       14                                   1.6 x 10-14        0.35 nA (06 nA Max)DET100A      NEW                 Si                       75.4 mm2 (Ø9.8 mm)       400 - 1100                             0.65 A/W @ 970 nm        43                                   5.5 x 10-14          600 nA Max
DET50B        NEW                Ge                       19.6 mm2 (Ø5.0 mm)      800 - 1800                             0.85 A/W @ 1550 nm      440                                 4 x 10-12             80 μA
DET10C        DET410         InGaAs                0.8 mm2 (Ø1.0 mm)        700 - 1800                              0.95 A/W @ 1550 nm      10                                   1.6 x 10-14         1 nA (25 nA Max)
DET10D        NEW I             nGaAs                 0.8 mm2 (Ø1.0 mm)      1200 - 2600                             1.1 A/W @ 2.3 μm            25                                    2 x 10-12            15 μA (75 μA Max)

Features
7 Models Cover the 150 nm to 2.6 μm Wavelength Range
High-Speed Response (Please see the Specs Tab for Details)
Easy-To-Use, Compact, and Versatile
Internal Bias Battery A23 (Included)
Thin Profile Allows Measurements in Tight Spaces
Includes Threaded Mount for Ø1" (Ø25 mm)
Accepts Ø1" Diameter Optics via SM1Threads
New Large Area and IR Versions Available