Newport's VA-BB series of broadband ultrafast variable attenuators provide continuous attenuation over a series of broad wavelength ranges. The VA-BB series is designed to provide high attenuation of linearly polarized fundamental and harmonic frequencies of light for most ultrafast oscillators. The VA-BB series is available in manual or motorized versions. The motorized version can be used in open- or closed-loop operation. 
The VA-BB series is based on zero-order half-waveplates and Glan-laser polarizers. For more detail on the principle of operation of these devices, please refer to Newport’s Application Note 26 – Variable Attenuator for Lasers. These attenuators are designed to handle average powers up to 100 Watts for wavelength ranges of 400 – 700 nm, 690 – 1040 nm, 650 - 1350 nm or 1000 – 1600 nm. 
The optics and high-precision opto-mechanics are incorporated into a compact housing, flexibly designed for post mounting at varying optical axis heights. P-polarized light is transmitted with minimal loss collinear to the input beam path while S-polarized light is rejected into a beam dump on the side of the housing. M-4 and 8-32 mounting threads are included on the bottom and one side of the housing. This allows for horizontally or vertically polarized output. 
The motorized versions of the VA-BB series come with a motorized rotary stage containing the half-waveplate. Software is included which allows the user to calibrate the VA-BB at a single wavelength.

新港的VA-BB系列宽带超快变衰减器在一系列宽波长范围内提供连续衰减。VA-BB系列被设计为为大多数超快振荡器提供线性偏振基频和光的谐波频率的高衰减。VA-BB系列可在手动或机动版本。电动版可用于开环或闭环操作。

VA-BB系列是基于零阶半波片和Glan-laser偏振器。有关这些装置的工作原理的更多细节，请参阅纽波特的应用说明26 -可变激光器衰减器。这些衰减器的平均功率可达100瓦，波长范围为400 - 700 nm, 690 - 1040 nm, 650 - 1350 nm或1000 - 1600 nm。

光学和高精度光学力学结合到一个紧凑的外壳，灵活设计后安装在不同的光轴高度。p偏振光以最小的损失共线传输到输入光束路径，而s偏振光被拒绝进入位于外壳一侧的光束转储。M-4和8-32安装螺纹包括在底部和外壳的一侧。这允许水平或垂直极化输出。

VA-BB系列的电动版本带有一个装有半波板的电动旋转台。软件允许用户在单一波长校准VA-BB。