Thorlabs的半波液晶可变延迟器(LCVR)将向列相液晶盒用作可变波片。由于没有移动部件,可实现毫秒级的快速响应时间(详情请看响应时间标签)。我们提供五种常用波长范围的增透膜:350 - 700 nm、650 - 1050 nm、1050 - 1700 nm、1650 - 3000 nm、2000 - 5000 nm或3600 - 5600 nm(透过率和延迟量数据,请看性能标签)。
Thorlabs提供两种通光孔径的尺寸:Ø10 mm和Ø20 mm。两种尺寸都有两种可变延迟范围可选:0 nm到λ/2的延迟,用于带残余延迟量补偿的延迟器;~30 nm到λ/2的延迟,用于无补偿的LC延迟器。我们有补偿的延迟器集成了由液晶聚合物制成的相位补偿器,可以补偿LCVR的残余延迟量,以在特定的驱动电压下达到真实零延迟量(更多信息,请看性能标签)。有关结构与原理,请看图1.2和1.3。
Ø10 mm延迟器的外径为1英寸,兼容我们的Ø1英寸光学元件安装座。此外,我们还有一款通光孔径Ø10 mm的未安装版特殊延迟器,适合OEM和其他特殊应用。Ø20 mm延迟器的外径为2英寸,兼容我们的Ø2英寸光学元件安装座。有关推荐的兼容安装座,请看规格标签。
性能
这些液晶可变延迟器均匀度良好,光损耗低且波前畸变小。此外,它们响应迅速,工作温度范围广,波长范围广。详情请见规格、性能和响应时间标签。我们同样提供热稳定半波延迟器,具有更好的长期稳定性能。
快速响应的Ø10 mm延迟器
Ø10 mm通光孔径的LCC1511-x无补偿和LCC1611-x有补偿LCVR采用不同的向列相液晶材料,响应速度比LCC1111-D、LCC1111-E1、LCC1111-MIR和Ø20 mm LCVR提高了超过3倍。
上一代Ø10 mm延迟器
如果您的应用不需要LCC1511-x和LCC1611-x LCVR的快速响应,可以联系技术支持获取上一代Ø10 mm通光孔径的延迟器,它们与Ø20 mm LCVR的规格相同,使用的也是相同的向列相液晶材料。详情请看定制能力标签。
工作
如图1.1所示,液晶可变延迟器由填满液晶(LC)分子溶液的透明液晶盒构成,用作可变波片。在未加电压的情况下,LC分子的取向由取向膜决定。取向膜由有机聚酰亚胺(PI)膜层构成,分子在制造期间沿摩擦方向排列。由于LC材料的双折射性,LC延迟器可以用作光学各向异性波片,机械外壳上标有慢轴,与延迟器的表面平行。液晶盒壁的两个平行面镀有透明导电膜,可在液晶盒上施加电压。施加交流电压后,LC分子会根据所施电压Vrms改变默认排列方向。因此,改变施加电压可以主动控制液晶可变延迟器的延迟。
残余延迟量补偿
由于PI层表面锚定,即使施加电压,仍有一些液晶分子无法改变方向,尤其是靠近取向膜层的分子。这样,LC延迟器在工作期间产生了残余延迟量。Thorlabs无补偿的LC延迟器在25 Vrms驱动电压下具有~30 nm的残余延迟量,如图1.2和1.3所示。为了满足敏感应用中真实零延迟量的需要,我们提供有补偿的LC延迟器。由液晶聚合物(LCP)构成的补偿层粘在液晶盒上,慢轴垂直于液晶盒的慢轴。LCP补偿层的固定延迟量为~50 nm。因此,特定驱动电压在5 V到20 V之间时,液晶盒与补偿器的延迟量相互抵消,产生真实零延迟量。但是,这样可能导致延迟均匀度稍微变低,总厚度增加。更多信息,请看规格和性能标签。
控制器
虽然采用交流电压(0到25 Vrms),但LCC25、LCC25D和KLC101控制器提供主动直流偏移补偿。直流偏移补偿自动将液晶设备的直流偏压置零,以抵消电荷积累。

图1.1 向列相液晶分子有序排列,分子呈现拉伸状,具有光学各向异性。施加电场时,分子沿电场排列,双折射的水平由液晶分子的倾斜控制。
Click to Enlarge
图1.2 无补偿的LC延迟器
Click to Enlarge
图1.3 有补偿的LC延迟器
无补偿的液晶延迟器的最小延迟量为~30 nm。我们有补偿的LC延迟器包含具有固定延迟和慢轴的液晶聚合物补偿器,慢轴与可变液晶盒的慢轴垂直。这样,我们有补偿的延迟器就可以实现0 nm的最小延迟。
| Selection Guide for LC Retarders | |
|---|---|
| Type | Clear Aperture |
| Half Wave | Ø10 mm or Ø20 mm |
| Half Wave, Thermally Stabilized | Ø10 mm |
| Full Wave | Ø10 mm or Ø20 mm |
| Full Wave, Thermally Stabilized | Ø20 mm |
| Multi-Wave | Ø10 mm |
| Multi-Wave, Integrated Controller | Ø10 mm |
| Custom LC Retarders | |
| Item # | LCC1611-A | LCC1421-A | LCC1611-B | LCC1421-B | LCC1611-C | LCC1421-C | |
|---|---|---|---|---|---|---|---|
| Wavelength Range | 350 - 700 nma | 650 - 1050 nm | 1050 - 1700 nm | ||||
| AR Coatingb | Ravg < 0.5% | ||||||
| Clear Aperture | Ø10 mm | Ø20 mm | Ø10 mm | Ø20 mm | Ø10 mm | Ø20 mm | |
| Housing Outer Dimensions | Ø1"c (Ø25.4 mm) | Ø2.20"d (Ø55.8 mm) | Ø1"c (Ø25.4 mm) | Ø2.20"d (Ø55.8 mm) | Ø1"c (Ø25.4 mm) | Ø2.20"d (Ø55.8 mm) | |
| Switching Time (Rise/Fall, Typical)e | 3.34 ms / 0.14 ms @ 25 °C, 635 nm | 15.8 ms / 260 µs @ 22 °C, 635 nm | 4.01 ms / 0.27 ms @ 25 °C, 780 nm | 34.0 ms / 360 µs @ 22 °C, 780 nm | 22.34 ms / 0.55 ms @ 25 °C, 1550 nm | 152 ms / 510 µs @ 25.6 °C, 1550 nm | |
| Damage Threshold | Pulsed (ns) | 1.0 J/cm2 (532 nm, 10 Hz, 8 ns, Ø200 µm) | 1.7 J/cm2 (810 nm, 10 Hz, 7.6 ns, Ø234 µm) | 1.2 J/cm2 (1542 nm, 10 Hz, 10 ns, Ø458 µm) | |||
| Pulsed (fs) | 0.01 J/cm2 (532 nm, 100 Hz, 76 fs, Ø162 µm) | 0.01 J/cm2 (800 nm, 100 Hz, 36.4 fs, Ø189 µm) | 0.08 J/cm2 (1550 nm, 100 Hz, 70 fs, Ø145 µm) | ||||
| Retardance Uniformity (RMS)f | < λ/20 @ 400 nm | < λ/20 @ 650 nm | < λ/20 @ 1050 nm | ||||
| Housing Thickness | 8.6 mm (0.34") | 15.0 mm (0.59") | 8.6 mm (0.34") | 15.0 mm (0.59") | 8.6 mm (0.34") | 15.0 mm (0.59") | |
| Wavefront Distortion | ≤λ/4 @ 635 nm | ||||||
| Surface Quality | 60-40 Scratch-Dig | ||||||
| Substrate Material | UV Fused Silica | ||||||
| Liquid Crystal Material | Nematic Liquid Crystal | ||||||
| Retardance Rangeg | 0 nm to >λ/2 | ||||||
| Operating Voltage (Max)h | 25 V | ||||||
| Parallelism | < 5 arcmin | ||||||
| Storage Temperature | -30 to 70 °C | ||||||
| Operation Temperature | -20 to 45 °C | ||||||
| Item # | LCC1111U-A | LCC1511-A | LCC1221-A | LCC1111U-B | LCC1511-B | LCC1221-B | |
|---|---|---|---|---|---|---|---|
| Wavelength Range | 350 - 700 nma | 650 - 1050 nm | |||||
| AR Coatingb | Ravg < 0.5% | ||||||
| Clear Aperture | Ø10 mm | Ø10 mm | Ø20 mm | Ø10 mm | Ø10 mm | Ø20 mm | |
| Housing Outer Dimensions | 17.0 mm × 12.0 mm (0.67" × 0.47") | Ø1"c (Ø25.4 mm) | Ø2"d (Ø50.8 mm) | 17.0 mm x 12.0 mm (0.67" x 0.47") | Ø1"c (Ø25.4 mm) | Ø2"d (Ø50.8 mm) | |
| Switching Time (Rise/Fall, Typical)e | 9.8 ms / 0.24 ms @ 25 °C, 635 nm | 2.72 ms / 0.16 ms @ 25 °C, 635 nm | 9.8 ms / 0.24 ms @ 25 °C, 635 nm | 19.52 ms / 0.44 ms @ 25 °C, 780 nm | 3.41 ms / 0.24 ms @ 25 °C, 780 nm | 19.52 ms / 0.44 ms @ 25 °C, 780 nm | |
| Damage Threshold | Pulsed (ns) | 1.0 J/cm2 (532 nm, 10 Hz, 8 ns, Ø200 µm) | 1.7 J/cm2 (810 nm, 10 Hz, 7.6 ns, Ø234 µm) | ||||
| Pulsed (fs) | 0.01 J/cm2 (532 nm, 100 Hz, 76 fs, Ø162 µm) | 0.01 J/cm2 (800 nm, 100 Hz, 36.4 fs, Ø189 µm) | |||||
| Retardance Uniformity (RMS)f | < λ/50 @ 400 nm | < λ/50 @ 650 nm | |||||
| Housing Dimensional Tolerance | ±0.4 mm | - | ±0.4 mm | - | |||
| Housing Thickness | 6.0 mm (0.24") | 8.0 mm (0.32") | 13.0 mm (0.51") | 6.0 mm (0.24") | 8.0 mm (0.32") | 13.0 mm (0.51") | |
| Wavefront Distortion | ≤λ/4 @ 635 nm | ||||||
| Surface Quality | 40-20 Scratch-Dig | ||||||
| Substrate Material | UV Fused Silica | ||||||
| Liquid Crystal Material | Nematic Liquid Crystal | ||||||
| Retardance Rangeg | ~30 nm to >λ/2 | ||||||
| Operating Voltage (Max)h | 25 V | ||||||
| Parallelism | < 5 arcmin | ||||||
| Storage Temperature | -30 to 70 °C | ||||||
| Operation Temperature | -20 to 45 °C | ||||||
| Item # | LCC1511-C | LCC1221-C | LCC1111-D | LCC1111-E1 | LCC1111-MIR | |
|---|---|---|---|---|---|---|
| Wavelength Range | 1050 - 1700 nm | 1650 - 3000 nm | 2000 - 5000 nm | 3600 - 5600 nm | ||
| AR Coatinga | Ravg < 0.5% | Ravg < 1.5% | Ravg < 1.0% | |||
| Clear Aperture | Ø10 mm | Ø20 mm | Ø10 mm | Ø10 mm | Ø10 mm | |
| Housing Outer Dimensions | Ø1"b (Ø25.4 mm) | Ø2"c (Ø50.8 mm) | Ø1"b (Ø25.4 mm) | Ø1"b (Ø25.4 mm) | Ø1"b (Ø25.4 mm) | |
| Switching Time (Rise/Fall, Typical)d | 21.29 ms / 0.50 ms @ 25 °C, 1550 nm | 95.8 ms / 1.81 ms @ 25.6 °C, 1550 nm | 192 ms / 1 ms @ 25.6 °C, 2200 nm | 290 ms / 11 ms @ 25 °C, 4400 nm | 372 ms / 14 ms @ 25.6 °C, 4400 nm | |
| Damage Threshold | Pulsed (ns) | 1.2 J/cm2 (1542 nm, 10 Hz, 10 ns, Ø458 µm) | 0.041 J/cm2 (2000 nm, 10 Hz, 6.5 ns, Ø292 µm) | - | ||
| Pulsed (fs) | 0.08 J/cm2 (1550 nm, 100 Hz, 70 fs, Ø145 µm) | 0.025 J/cm2 (2000 nm, 100 Hz, 100 fs, Ø220 µm) | - | |||
| Retardance Uniformity (RMS)e | < λ/50 @ 1050 nm | < λ/30 @ 1650 nm | < λ/10 @ 3600 nm | < λ/10 @ 3600 nm | ||
| Housing Thickness | 8.0 mm (0.32") | 13.0 mm (0.51") | 8.0 mm (0.32") | 8.0 mm (0.32") | 8.0 mm (0.32") | |
| Wavefront Distortion | ≤λ/4 @ 635 nm | - | ||||
| Surface Quality | 40-20 Scratch-Dig | 60-40 Scratch-Dig | 40-20 Scratch-Dig | 60-40 Scratch-Dig | ||
| Substrate Material | UV Fused Silica | Silicon | Germanium | |||
| Liquid Crystal Material | Nematic Liquid Crystal | |||||
| Retardance Rangef | ~30 nm to >λ/2 | |||||
| Operating Voltage (Max)g | 25 V | |||||
| Parallelism | < 5 arcmin | |||||
| Storage Temperature | -30 to 70 °C | |||||
| Operation Temperature | -20 to 45 °C | |||||
