The S370C and S470C Thermal Sensors are designed to measure short and highly energetic laser pulses. All of these units are post-mountable for free-space applications and feature NIST-traceable data stored in the sensor connector.
These thermal power sensors are unique in that they have thermal volume absorbers, where our other thermal power sensors have thermal surface absorbers. The volume absorber consists of a Schott glass filter. Incident pulses are absorbed and the heat is distributed throughout the volume. In this way, pulses that would have damaged the absorption coating of a thermal surface absorber are safely measured by these thermal volume absorbers.
The S370C features a large Ø25 mm aperture ideal for large-spot-size beams, and it is compatible with average powers from 10 mW to 10 W (CW).
In comparison, the S470C is faster, as the glass absorber volume is reduced and other design parameters have been optimized for speed. This results in a different optical power range, with the ability to measure powers down to 100 µW. The Ø15 mm aperture is of the S470C is smaller, and it has a lower max average power of 5 W. Its 10 µW resolution is better than the 250 µW resolution of the S370C.
Thorlabs offers a recalibration service for these sensors, which can be ordered below (see Item # CAL-S200).
This absorption curve is shown over a broader wavelength range than the sensors' operating ranges.
See the table for the operating wavelength range of each sensor.
|Wavelength Range||400 nm - 5.2 µm||250 nm - 10.6 µm|
|Optical Power Range||10 mW - 10 W (15 Wb)||100 µW - 5 W (Pulsed and CW)|
|Input Aperture Size||Ø25 mm||Ø15 mm|
|Active Detector Area||Ø25 mm||Ø16 mm|
|Max Optical Power Density||35 W/cm² (Avg.); 100 GW/cm² (Peak)|
|Detector Type||Thermal Volume Absorber (Thermopile)|
|Resolutionc||250 µW||10 µW|
|Measurement Uncertaintyd||±3% @ 1064 nm
±5% @ 400 nm - 1064 nm
|±3% @ 1064 nm
±5% @ 250 nm - 10.6 µm
|Response Timee||45 s
(3 s from 0 to 91%)
(<2 s from 0 to 90%)
(Without Adapter, if Applicable)
|75 mm x 75 mm x 51.2mm
(2.95" x 2.95" x 2.02")
|45.0 mm x 45.0 mm x 18.0 mm
(1.77" x 1.77" x 0.71")
(In Sensor Head)
|Cable Length||1.5 m|
|Post Mounting||M6 Threaded Taps, Includes
Ø1/2" Post, 75 mm Long
|Universal 8-32 / M4 Tap
(Post Not Included)
|30 mm Cage Mounting||Four 4-40 Tapped Holes||-|
|Aperture Threads||-||External SM1|
|Accessories||Externally SM1-Threaded Adapter||-|
|Compatible Consoles||PM400, PM200, PM100A, PM100USB, and PM320E|