T-SWEEPER

• 0.05–4.0 THz frequency range

• Up to 70 traces/s with >2 THz bandwidth

• Measurement rate up to 500 Hz

• No moving parts for high reliability

• Deep penetration for thick polymers and ceramics

• Scalable to up to 8 channels

• Supports long fiber connections for remote sensing

Rapidly swept lasers offer an alternative to established distributed feedback diodes for applications in which measurement speed is more relevant than frequency resolution. One implementation combines a fast, widely tunable laser and a static source into a “frequency-modulated continuous-wave” (FMCW) terahertz system. Equipped with state-of-the-art photomixers, the system acquires spectra with more than 2 THz bandwidth in less than 15 ms. Akin to pulsed systems, trace averaging reduces the noise floor and consequently broadens the usable frequency range: With 2 minutes of averaging, the bandwidth increases to more than 3.5 THz. Users can conveniently set the number of averages in the control software and therefore optimize system performance with respect to either measurement speed or dynamic range and bandwidth. An important difference from pulsed systems: The fast FMCW unit utilizes an InGaAs-based p-i-n photodiode as a terahertz emitter, and consequently, the spectrum peaks at approximately 0.1 THz—significantly lower than the 1.0 THz peak of pulsed spectra. Owing to the lower peak frequency, the signals generated by the fast FMCW unit have a higher penetration depth in many polymers, a property that makes the system particularly attractive for thickness measurements on thick samples.

System Type: FMCW THz System Frequency Range: 0.05–4.0 THz Measurement Rate: Up to 500 Hz Trace Rate: Up to 70 traces/s Bandwidth: >2 THz THz Emitter: InGaAs p-i-n Photodiode Channels: Up to 8 Fiber Connection: Long-distance compatible Design: No Moving Parts

• Non-Destructive Testing (NDT)

• Thickness Measurement

• Plastic & Composite Inspection

• Paint & Coating Inspection

• Inline Industrial Inspection

• Synthetic Aperture Radar (SAR)

• Large-Area / Multi-Channel Inspection