公开(公告)号：US06646746B1

公开(公告)日：2003-11-11

申请号：US09678432

申请日：2000-10-02

申请人： Wayne V. Sorin ,  Bogdan Szfraniec ,  Douglas M. Baney

发明人： Wayne V. Sorin ,  Bogdan Szfraniec ,  Douglas M. Baney

IPC分类号： G01J345

CPC分类号： H04B10/60 ,  G01J9/04 ,  H04B10/64

摘要： An optical heterodyne detection system in accordance with an embodiment of the invention includes two optical receivers for separately measuring the power of an input signal and a local oscillator signal before the signals are combined. The measurements of the input signal and the local oscillator signal are then utilized to enhance the heterodyne signal to noise ratio by removing the intensity noise contributed by the input signal and the local oscillator signal. By measuring portions of the input signal power and the local oscillator signal power and then subtracting out the scaled quantities from the photocurrent measurement during signal processing, the signal to noise of the heterodyne signal is improved beyond that which is accomplished by known balanced receivers.

摘要翻译： 根据本发明实施例的光外差检测系统包括两个光接收器，用于在组合信号之前单独测量输入信号的功率和本地振荡器信号。 然后通过去除由输入信号和本地振荡器信号贡献的强度噪声来利用输入信号和本地振荡器信号的测量值来增强外差信噪比。 通过测量输入信号功率和本地振荡器信号功率的部分，然后在信号处理期间从光电流测量中减去定标数量，外差信号的信噪比被改善，超过了已知的平衡接收机所完成的。

公开(公告)号：US06486961B1

公开(公告)日：2002-11-26

申请号：US09851758

申请日：2001-05-08

申请人： Bogdan Szfraniec ,  Douglas M. Baney

发明人： Bogdan Szfraniec ,  Douglas M. Baney

IPC分类号： G01B902

CPC分类号： G01M11/3172

摘要： A system and method for measuring the group delay of an optical device under test (DUT) utilizes an optical frequency counter in conjunction with a test interferometer to compensate for the non-uniform frequency changes of an input optical signal used by the test interferometer to measure the group delay. The group delay of the optical DUT is measured using the zero-crossings of an AC coupled heterodyne beat signal produced by the test interferometer from the input optical signal. In the measurement of the group delay, phase changes in the heterodyne beat signal caused by the non-uniform frequency changes of the input optical signal are compensated by using the measured optical frequency of the input optical signal. The optical frequency is detected by the optical frequency counter. The detected optical frequency is indicative of the non-uniform frequency changes of the input optical signal.

摘要翻译： 用于测量被测光学器件（DUT）的组延迟的系统和方法利用与测试干涉仪相结合的光频计数器来补偿由测试干涉仪用于测量的输入光信号的不均匀频率变化 群延迟 使用由测试干涉仪从输入光信号产生的AC耦合外差拍频信号的过零点来测量光学DUT的组延迟。 在组延迟的测量中，通过使用测量的输入光信号的光频率来补偿由输入光信号的非均匀频率变化引起的外差拍频信号的相位变化。 光频率由光频计数器检测。 检测到的光频率表示输入光信号的不均匀频率变化。