K9(Bk7)
K9(BK7)具有优良的机械性能和非常低的气泡k9(b270)产品图和杂质，具有良好的抗划伤性。由于其化学性能稳定，无需特殊处理研磨和抛光。 应用于光电子、微波技术、衍射光学元件等众多领域。
| 属性 | 说明 |
| 传输范围 | 0.4µm to 2.5µm |
| 密度 | 2.51 g/cc |
| 热膨胀 | 7.1x10-6 /°k @ -30° + 70°c, & 8.3x10-6 /°k @ 20°c to 300° |
| 表面抛光 | bk-7 polishes extremely well & polishes of 10-5, or 20-10 scratch-dig are achieved at extra costs respectively, mainly for uv & visible applications. |
| 曲面图 | surface figure of 1/10 wave to 1/4 wave @ 0.6328µm are specified mostly on lenses for ultraviolet & visible use. |
| 涂层 | ar @ 0.8-2.5µm, ar @ 1.064, ar @ visible wavelength. |
| 应用 | 天文，热成像 |
| 生产的产品 | 镜片，棱镜，滤光片，过滤器等. |
| 波长 | 折射率(n) |
| 0.4047 | 1.530 |
| 0.4800 | 1.523 |
| 0.5461 | 1.519 |
| 0.6328 | 1.515 |
| 0.8521 | 1.510 |
| 1.0600 | 1.507 |
| 1.5300 | 1.501 |
| 1.9700 | 1.495 |
| 2.3250 | 1.489 |
中国-K9：Nd:1.516371 Vd:64.13356
肖特-BK7：Nd:1.516800 Vd:64.169998
HOYA-BSC7：Nd:1.516800 Vd:64.2