Table 1.
Comparison between the key features of typical mid-IR spectrometers based on OPO/DFG generated combs and QCL generated combs
| Specification | mid-IR spectrometers based on OPO/DFG combs | mid-IR spectrometers based on QCL combs |
|---|---|---|
| Possible spectral coverage | 2.5–12 µm | 5–12 µm |
| Spectral bandwidth | Up to ~ 1500 cm−1 | Up to ~ 150 cm−1 |
| Spectral tunability | Yes | No |
| Typical repetition rate (spectral sampling) | ~ 100 MHz | ~ 10 GHz |
| Average output power | Up to ~ 250 mW | Up to ~ 1 W |
| Detection sensitivity | High (w/cavity enhancement) | Low (w/o cavity enhancement) |
| Complexity | High | Low |
| Size | Bulky | Compact |
| Cost | Expensive | Inexpensive |