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Optics & Infrared Sensing

Optics & Infrared Sensing

Optical Characterization

Long Wave Infrared Metrology

The development of active and passive components needed to make useful devices in the mid- and long-wave infrared require specialized optics that are not readily available from catalog sources. For instance, the wide fast axis divergence of QC Lasers requires custom designed aspheres for efficient light collection and collimation. Since, there are no commercially available LWIR metrology tools, PNNL has developed a metrology suite to measure the performance of custom LWIR optical components that include:

  1. Scanner to measure fast- and slow-axis emission profile of a QCL, providing input for custom lens design.
  2. LWIR Twyman-Green interferometer to measure transmitted wavefront aberrations at the operating waveglength range.
  3. Scanner to measure the fast- and slow-axis spot size, beam propagation metric (M2), and intrinsic laser astigmatism.
Figure 1 Schematic of apparatus for measuring divergence of Quantum Cascade Lasers (QCLs)
Figure 1 Schematic of apparatus for measuring divergence of Quantum Cascade Lasers (QCLs)
Figure 2  Typical divergence measurements along the fast (blue) and slow (axis) of a QCL
Figure 2 Typical divergence measurements along the fast (blue) and slow (axis) of a QCL
Figure 3  The iterative process of measuring designing and characterizing the custom aspheres for QCL applications
Figure 3 The iterative process of measuring designing and characterizing the custom aspheres for QCL applications
Figure 4  Focal spot size measurements for the slow (left) and fast (right) axis of a QCL
Figure 4 Focal spot size measurements for the slow (left) and fast (right) axis of a QCL
Figure 5  Measuring the beam propagation metric (M2) and astigmatism of a QCL
Figure 5 Measuring the beam propagation metric (M2) and astigmatism of a QCL

Optics & Infrared Sensing

Capabilities