Redefining optical thermal conductivity measurements

Turnkey Implementation with Laser Thermal's SSTR-F

Steady-State Thermoreflectance in Fiber Optics:

Get access to streamlined thermal conductivity measurements, from thin film to bulk, using our patented fiber-optic-based steady-state thermoreflectance tool. The automated, high throughput, turn key implementation of SSTR-F can measure the thermal conductivity of materials with values ranging from 0.05 to 500 W/m/K.
Absolute measurement of thermal conductivity (no knowledge of heat capacity or density required for analysis).
Interfacial thermal resistance and thin film measurements from nanometers to microns.
Automated, rapid, high throughput testing with micron areal resolution.
Simplified, user friendly, non-contact approach to thermal conductivity testing.

SSTR-F Specifications:

Materials Solids and Liquids
Thermal Conductivity Range 0.05 to 2500 W/m•K
Directional Measurement Through-thickness and In-plane
Spot Size Up to 100 microns
Temperature Range 80K – 600K
Accuracy 5%
Repeatability 2%
Advanced Thermal MappingThermal conductivity solutions

Laser Thermal’s SSTF-F measures thermal conductivity using the combination of laser based thermoreflectance techniques with traditional steady-state thermal testing concepts using the Hopkins Analysis. Harnessing decades of knowledge regarding the relationship between temperature and the thermoreflectance of metals, laser heating of a thin metal film on a material of interest allows for determination of the thermal conductivity of the underlying material without knowledge of the material’s heat capacity by probing the response of the metal due to the pump. These concepts, laser based pμmp-probe experiments, have been utilized for decades to measure various optical, mechanical, and thermal properties of materials.

Unlike most traditional free-space (exposed laser beams) pump-probe experiments, SSTR-F incorporates all of its active and passive components in fiber-optic leading to a compact, simple system with increased safety, no need for prior optical experience, and streamlined high throughput measurements.

The technique works in principle by inducing a steady-state temperature rise in a material via long enough exposure to heating from a pump laser. A probe beam is then used to detect the resulting change in reflectance, which is proportional to the change in temperature at the sample surface. Increasing the power of the pump beam to induce larger temperature rises, Fourier’s law is used to determine the thermal conductivity.

  • Standard Features
  • Physical Characteristics
  • Additional Features

Thermal conductivity range

0.05 – 500 W m-1 K-1


+/- 2%

Included Hardware

Computer, Monitor, and Keyboard


+/- 10%


Better than 2.0%

Standard Objective


Data Analysis

Interfacial Resistance and Thermal Conductivity


Focus and sample alignment


31” x 36” x 57” (W x D x H) not including computer control

Power Requirements

110/220 VAC, 50/60 Hz, 15 Amp


200 lbs (nominal, varies by options)

Optical Classification

Class I or Class III laser product

Automated X-Y motion

Up to 300 mm x 300 mm

Additional Objectives

2X, 5X, 20X, and 50X

Temperature Testing

Room temperature up to 200 °C

Objective Switching Assembly

Allows for automatic switching between two objectives for increased automation

Laser Thermal's SSTR-F

Nanoscale to bulk

- Interfacial thermal resistance
- Thin films
- Substrates

Turnkey testing

- Full automation
- Stream-lined analysis
- Single micron areal resolution

Unparalleled reliability

- Accuracy +/- 10%
- Repeatability +/- 0.5%
- Reproducibility +/- 1%

Validated results

- Validated against NIST CRM material Pyroceram 9606
- Bulk measurements at small volumes
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