Optical spectrum analyser offers 'best in class' optical performance

Yokogawa's AQ6370C combines exceptional accuracy and resolution with ultra-high dynamic range, comprehensive interfacing and ease of use

The new AQ6370C is an optical spectrum analyser offering the world's 'best in class' optical performance combined with excellent functionality and operability for applications including R&D and production testing of optical devices and transmission systems.It comes from the Yokogawa T&M stable.

Covering the wavelength range from 600 to 1700nm and applicable to both single-mode and multimode fibres, it provides unprecedented optical performance, including high wavelength accuracy of ±0.01 nm, high wavelength resolution of 0.02 nm, ultra-high dynamic range of 78 dB (typical), wide level range of -90 dBm, and fast sweep speed of 0.2 sec/100 nm.

Enhanced functionality and operability are provided by a large, bright LCD screen, easy operation via panel keys and a mouse, four USB ports including memory, mouse and keyboard interfaces, and high-speed GPIB and Ethernet remote interfaces. The instrument also has a built-in wavelength reference source and a range of integral analysis functions.

The ultra-high dynamic range (typically 80 dB) results from an enhanced stray-light suppression ratio in the monochromator, and results in reduced measurement times. The higher-performance model can also achieve a higher dynamic range within 0.2 nm of the peak wavelength. With the sharper spectral characteristics of the monochromator, spectral signals in close proximity can be separated clearly and measured accurately.

The wide level range from +20 dBm to -90 dBm means that the AQ6370C can measure high power sources such as optical amplifiers and pump lasers for Raman amplifiers as well as very weak optical signals. Measurement sensitivity can be selected from seven categories according to the application and measurement speed requirement.

In addition to improved level sensitivity of -85 dBm (from 1000 to 1300 nm), the AQ6370C incorporates a smoothing function to reduce noise on the measured spectrum and a high dynamic mode which obtains a better dynamic range by reducing the influence of stray light caused when the input is a strong optical signal.

The free space input allows multimode and single-mode fibre measurements to be carried out on the same instrument. In addition, the low insertion loss for multimode fibre available with the AQ6370C also helps to maintain the excellent measurement efficiency. The low insertion-loss variation at the input connector increases the measurement repeatability, and the lack of physical contact means that no damage is incurred in connecting the fibres. An APC level correction function is also included to correct the level offset resulting from the insertion loss of an angled PC (physical contact) connector.
With an advanced monochromator, faster electrical circuits, and noise reduction techniques, the AQ6370C achieves high measurement speed even when measuring a steep spectrum from DFB-LD or DWDM signals, or when measuring a low-power signal from a broadband light source. Efficiency is further enhanced by the high-speed Ethernet and GP-IB remote interfaces.

A combination of wide span sweep with high resolution results from the availability of 50,001 data sampling points, which makes measurements easier and more efficient. Ease of operation also benefits from the ability to carry out trace zooming and the combination of mouse and keyboard operation.
USB interfaces support large-capacity removable memory and hard disk drives in addition to the 512 Mbyte of internal memory: sufficient for over 20,000 traces. Data handling is further eased by the 'all at once' trace filing, which allows all seven traces to be saved simultaneously in one file.

Analysis functions include calculations between traces, maximum/minimum hold, and 13 spectral analysis functions for popular applications such as spectral width analysis, WDM analysis, filter analysis and LED analysis. A macro programming function allows multiple analyses to be combined and executed automatically as well as forming the basis for building automated test systems.
The AQ6370C can compensate for ambient condition changes, vibration and shock through a combination of the built-in wavelength reference source, a wavelength calibration function and an optical alignment function.

The overall high performance of the AQ6370C allows it to be used for both R&D and manufacturing tests on optical devices and systems including active devices such as lasers, amplifiers and transceivers, passive devices such as filters and fibres, and optical transmission equipment for DWDM and CWDM transmission.

Two versions of the AQ6370C are available, differing only in wavelength accuracy and dynamic range: the standard AQ6370C-10 and the higher-performance AQ6370-20.