Fibre Adaptor Improves Optical Input of Spectrum Analysers

A new adaptor for use with the Yokogawa AQ6370 Series of optical spectrum analysers (OSAs) is designed to enhance
the sensitivity, dynamic range and level stability by reducing the divergence of light emitted from the input fibre and
increasing the input signal to the OSA by 5 dB.

The light that is emitted from an optical fibre is divergent, and under normal conditions the limited size of the optics
inside the OSA monochromator results in divergent light being blocked, and hence unable to contribute to a strong
optical signal.

Using the new fibre NA adaptor on a GI50/125 multi-mode fibre results in the fibre’s numerical aperture (NA) value
being divided by two. The reduction in divergence of the optical input increases the monochromator optical
throughput, producing a 5 dB (factor 3) increase in signal strength.

The result of this enhancement in performance is better dynamic range in passive component testing and better
level stability in active device testing. The Yokogawa AQ6370 Series of optical spectrum analysers offer 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.

Covering the wavelength range from 350 to 2400nm and applicable to both single-mode and multimode fibres, the
AQ6370 Series provides unprecedented optical performance, including high wavelength accuracy of ±0.01nm, high wavelength resolution of 0.02nm, ultra-high dynamic range of 78 dB (typical), wide level range of -90 dBm, and fast sweep speed of 0.2 sec/100nm.