The OSA-155 DWDM System Analyzer is ideal for measurements on broadband multi-channel optical connections operating at wavelengths between 1450 nm and 1650 nm. The OSA-155 can be used on DWDM systems (Dense Wavelength Division Multiplexing) with channel spacings of 0.4 nm/50 GHz or above. The maximum permitted total input level of +30 dBm allows measurements to be made on systems having high channel power levels. The main application for the OSA-155 is for analyzing optical spectra. The wavelength or frequency, power level and signal to noise ratio of each channel can be determined automatically. Functions for investigating the variation of the optical parameters with time are also provided. Instruments fitted with a monitor output (BN 2260/04) can select out a single WDM channel and make it available for further measurements. This makes it possible to perform measurements on the digital signal itself (e.g. bit error rate, pointers, jitter / wander, etc.) using a SDH / SONET tester equipped with optical interfaces, such as the ANT-20. Features The OSA-155 is a PC-based measuring instrument fitted into a rugged casing. The instrument is designed for mobile use and can be operated using the touchscreen. When used in the laboratory, the OSA-155 can be operated just like any normal PC. The following peripherals can be connected to it; * Mouse • Keyboard * Printer • Monitor 1.2.1 Measurement software The software is pre-instalied. The software for the standard instrument is split into three operating modes: * GRAPH mode: The spectrum is displayed graphically. The traces can be measured and prepared for producing a measurement record. * WDM mode: The individual channels are identified and measured automatically. Wavelength, frequency and power level can be investigated. Statistical functions are also provided for this purpose. The data obtained is displayed in table form. . FILTER mode (Version BN 2260/04): The filter of the OSA-155 can be set to a fixed wavelength. The signal thus filtered out from the mixture of wavelengths is available from a monitor output and can be further analyzed e.g. using an ANT-20. * All configuration settings can be handled clearly and simply in CONFIGURATION mode. Power supply The OSA-155 can be powered from three different sources: » AC Sine power supply having a nominal voltage between 100 V to 120 V and 200 V to 240 V • External DC supply voltage between 12 V and 26 V (e.g. on-board vehicle power supplies or an external AC adapter, minimum 60 W) • Built-in rechargeable batteries The instrument selects the available power source automatically. The built-in rechargeable batteries take over if the external supply fails. The instrument reverts to AC powering as soon as the supply is restored. The instrument manages the batteries in such a way so as to ensure optimum performance, so that little maintenance is needed and maximum capacity is always available. 1.2,3 Function The OSA-155 filters the input signal using a variable monochromator. The monochromator (refraction grating) has a resolution of 0.1 nm /12.5 GHz. The OSA-155 measures the intensity of the filtered signal while the monochromator is scanning. The instrument includes an internal reference source which it uses to calibrate the wavelength measurement automatically. An optical switch is used to switch from the input to the internal reference source for this purpose. Instruments equipped with a monitor output (version BN 2260/04) use a further optical switch to pass the filtered signal from the detector to the monitor output.