ZnS多光谱窗片

ZnS多光谱窗片

ZnS多光谱（透明）用于红外窗口和热波段（8至14μm）透镜，特别是需要更大透射和更低吸收率的窗口。 选择用于可见对准也是有利的。

硫化锌通过从锌蒸汽和H ₂ S气体合成而产生，经过压片形成片状。硫化锌在结构上是微晶的，控制晶粒尺寸以产生最大强度。 多光谱等级然后是热等静压（HIP），以改善中红外透射和产生视觉上清楚的形式。 单晶ZnS是可用的，但不常见。在其常用光谱范围内, 散射很低。在用做高功率激光器件时, 需要严格控制材料的体吸收和内部结构缺陷, 并采用最小破坏程度的抛光技术和最高光学质量的镀膜工艺。

ZnS在300℃下显著氧化，在约500℃下显示塑性变形，并解离约700℃。 为了安全起见，在正常大气中不应在250°C以上使用硫化锌窗户。

详细参数：

透射范围：                               0.37?13.5μm

折射率：                               2.20084  at 10μm

反射损耗：                   24.7％ at 10μm（2个表面）

吸收系数：                     0.0006cm ^-1 at 3.8μm

吸收峰：                                   30.5μm

dn / dT：                    + 38.7×10 ^-6 /℃，3.39μm

dn /dμ：                                      n / a

密度：                                      4.09g / cc

熔点：                                       1827°C

热导率：                         27.2W m^-1 K^-1  at 298K

热膨胀：                         6.5×10^-6 /℃ at 273K

硬度：                           Knoop 160  with 50g indenter

比热容量：                             515JKg^-1K^-1

介电常数：                                     88

杨氏模量（E）：                        74.5GPa

剪切模量（G）：                          n / a

体积模量（K）：                          n / a

弹性系数：                                not available

表观弹性极限：                   68.9MPa（10,000psi）

泊松比：                                   0.28

溶解度：                         65×10^-6g / 100g  water

分子量：                                  97.43

类/结构：                      HIP多晶立方，ZnS，F42m

折射率：

No = Ordinary Ray

ZnS多光谱（透明）圆形窗片

ZnS多光谱（透明）矩形窗片

关于晶体切割：

During Chemical Vapour Deposition the small crystallite grains align with the direction of growth, and are

normal to the thickness of the sheet produced. For windows of normal thickness and aspect ratios the alignment of the grain therefore is rarely a problem as they are cut from the grown sheet such that within an optical window the grains align perpendicular to the surfaces. This is optimum orientation for lowest internal absorption and scatter.

With prisms, the cutting direction requires more consideration. It is recommended that the thickness of the strip material corresponds to the apex height of the prism. This ensures optimum crystallite orientation for most usual

prism applications.

For typical 45° prisms the most obvious use of material is shown in (A) but it

should be noted that this is not the optimum orientation.

The best choice is (B) and it also permits a higher limit on prism size or conversely allows thinner stock to be used. There is waste at the ends of the strip but this is small and so it may not be quite as economic as (A).

Cutting in direction (C) where the entire light beam runs at 90° to the grain

structure should be avoided completely if at all possible. Note that maximum available thickness of ZnSe and ZnS (FLIR) is approximately 60mm. Maximum available thickness of ZnS Cleartran is approximately 30mm