Thorlabs' Low Group Delay Dispersion (GDD) Mirrors are designed to minimize pulse broadening in ultrafast applications. When mounted at a 45° angle of incidence, our Low GDD Mirrors provide a reflectance of greater than 99% and a low GDD of less than |30 fs2| in the 1400 nm - 1700 nm wavelength range (see the Graphs tab for more details). These ultrafast mirrors are intended for use with erbium lasers (1530 - 1620 nm).
Features
- Low Group Delay Dispersion: |GDD| < 30 fs2
- Ideal for Pulses Shorter than 250 fs
- Reflectance Greater than 99%
- Ø1/2", Ø1", and Ø2" Mirrors Available
- Polished (Ø1/2" and Ø1") or Fine Ground (Ø2") Back Surface
These low GDD mirrors are available with 1/2", 1", and 2" diameters. The edge of each optic is engraved with the item number and an arrowhead pointing to the coated surface. While the back surface of the Ø2" mirror is fine ground, the back surface of the Ø1/2" and Ø1" mirrors is polished so that the small fraction of light that transmits through the reflective coating may be used for applications such as power monitoring.
Specifications:
| Item # | UM05-45C | UM10-45C | UM20-45C |
|---|---|---|---|
| Design Wavelength Range | 1400 - 1700 nm | ||
| Diameter | 1/2" (12.7 mm) | 1" (25.4 mm) | 2" (50.8 mm) |
| Diameter Tolerance | +0.00 / -0.10 mm | ||
| Thickness | 6.4 mm (0.25") | 9.5 mm (0.37") | 12.0 mm (0.47") |
| Thickness Tolerance | ±0.20 mm | ||
| Clear Aperture | >80% of Diameter | ||
| Reflectance | Rs > 99% (1400 - 1700 nm) Rp > 99% (1500 - 1600 nm) |
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| Angle of Incidence | 45° | ||
| Group Delay Dispersion | |GDDs| < 30 fs² (1400 - 1700 nm) |GDDp| < 30 fs² (1500 - 1600 nm) |
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| Substrate | Fused Silica | ||
| Front Surface Flatness | λ/4 at 632.8 nm Over Clear Aperture |
λ/8 at 632.8 nm Over Clear Aperture |
λ/3 at 632.8 nm Over Clear Aperture |
| Front Surface Quality | 15-5 Scratch-Dig | 20-10 Scratch-Dig | |
| Parallelism | ≤3 arcmin | ||
| Back Surface | Polished | Fine Ground | |
For further information, please contact