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NEP (noise equivalent power) - NEP（噪声等效功率）
NEP 是相当于器件噪声水平的入射光量。换言之，它是获得 1 信噪比 (S/N) 所需的光量。我们将在最大灵敏度波长 (λp) 下定义 NEP 值。由于噪声水平与频带的平方根成正比，因此带宽被归一化为 1 Hz。$$ NEP[\frac{W}{Hz^{\frac{1}{2}}}]=\frac{噪声电流[\frac{A}{Hz}]}{λp \ 下的感光灵敏度 [\frac{A}{W}]}$$
NGN (next generation network) - NGN（下一代网络）
这是利用 IP（互联网协议）技术的下一代信息通信网络，旨在通过融合固定电话、移动电话、数据通信等来提供多媒体服务。除了传统电话网络具备的可靠性和稳定性外，NGN 还将提供与 IP 网络相同的灵活性和经济效率。
Node sensitivity - CCD - 节点灵敏度 - CCD
CCD 输出处电子与电压的转换比，单位为 uV/电子。
Noise - CCD - 噪声 - CCD
CCD 输出处电子与电压的转换比，单位为 uV/电子。
CCD 中有很多噪声源，包括宇宙射线等外在因素。仅考虑 CCD 元件中的固有噪声时，这些噪声可分为以下四种因素：
- 1. 固定模式噪声 (Nf)
- 2. 光子散粒噪声 (Ns)
- 3. 暗散粒噪声 (Nd)
- 4. 读出噪声 (Nr)
Nt = (Nf 2 + Ns2 + Nd2 + Nr2 ) 1/2 Nt：总噪声。注：计算一个像素的噪声时，Nf = 0
上图显示了这四种因素与曝光量的关系。无论入射光子数如何，只要曝光时间不变，暗电流产生的暗散粒噪声就总是恒定的。同样，读出噪声与曝光量无关，因为它仅由 CCD 输出方法决定。
在暗散粒噪声降低到读出噪声以下的条件下操作 CCD 时，CCD 的性能可以增强到其探测限（读出噪声）。在 MPP 模式下工作时对 CCD 进行冷却是降低暗电流的最有效方法。较高曝光量时的固定模式噪声和较低曝光量时的散粒噪声决定了工作期间的信噪比。影响探测限的噪声因素是暗散粒噪声和读出噪声。由于暗散粒噪声在很大程度上取决于暗电流，如果将其充分最小化，读出噪声最终将制约探测限或下一节中讨论的动态范围最低水平。
Noise - NMOS linear image sensor - 噪声 - NMOS 线阵图像传感器
NMOS 图像传感器噪声主要分为固定模式噪声和随机噪声。
固定模式噪声包括尖峰噪声和暗电流。尖峰噪声是在输入寻址脉冲时，通过 MOS 开关的漏极到栅极电容在视频线上产生的开关噪声。当指定读出条件时，此噪声的大小是恒定的，因此可以通过信号处理软件从每个像素中减去它们。相比之下，随机噪声可追溯到信号输出过程中引起的电压、电流或电荷的错误波动。这种随机噪声可能发生在图像传感器内部以及读出电路中。当从外部电路减去固定模式噪声时，随机噪声决定图像传感器的光探测下限或动态范围的下限。
考虑到实际操作过程中的性能，通过测量从读出电路而不是仅从图像传感器导出的总随机噪声来测试和评估滨松 NMOS 图像传感器。
噪声水平以等效输入噪声或 ENI 表示，该值转换为图像传感器的输入电荷单位。这些单位是电子数的均方根值（电子 r.m.s.）。
Noise - Photodiode - 噪声 - 光电二极管
与其他类型的光传感器一样，光电二极管的光探测下限由该器件的噪声特性决定。光电二极管中的噪声是分流电阻的热噪声（或约翰逊噪声）ij 和由暗电流和光电流产生的散粒噪声 isD 和 isL 的总和。
Noise - Photomultiplier tube - 噪声 - 光电倍增管
与其他类型的光传感器一样，光电倍增管的光探测下限由该器件的噪声特性决定。PMT 中的噪声是由暗电流和光电流的统计波动引起的，称为散粒噪声。光电倍增管增益对噪声的影响非常小。
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