Advantest Q8344A Fiber Optic Spectrum Analyzer

Optical Measuring Instruments and Optical Device Test Systems

Optical Spectrum Analyzer for Coherent Measurements

■Coherence measurement

■High-speed measurements at 1.5 sec/scan

Wide wavelength range from 0.35 micron to 1.75 micron

■Wavelength measurement accuracy of 0.1 nm

The Q8344A is an optical spectrum analyzer with a wide wavelength range from 0.35 to 1.75 µm.

By using a Fourier spectroscopy system with a Michelson interferometer,

it is possible to analyze coherence that cannot be obtained with a dispersive spectroscopy system using a monochromator.

It demonstrates the ability to evaluate laser diodes for optical and video disks.

The Optical Measurement Instruments and Optical Devices Test System

has a built-in He-Ne laser used as a reference wavelength with a wavelength accuracy of ± 0.1 nm (1.3 µm),

which ensures long-term measurement stability even without wavelength calibration.

With a maximum wavelength resolution of 0.05 nm (0.85 µm), the Q8344A is suitable

for measuring laser diodes with narrow mode intervals.

Measurement speeds of about 1.5 seconds (0.4 to 1.05 µm and 0.8 to 1.75 µm)

are independent of the analysis span, so it can be used as a system component.

With its versatile display, analysis, and processing capabilities,

the Q8344A can be used for a variety of component characterization applications,

from light-emitting components such as laser diodes and LEDs to optical components such as optical fibers and filters.

Coherent Measurements

Since the Q8344A uses a Michelson interferometer, it can be used for coherence measurements.

This feature makes it easy to evaluate the performance of noise suppression caused by

the return light of laser diodes in video disks.

An analysis range of approximately ±10 mm enables measurement of

the coherence length of SLDs (Super Light Emitting Diodes) used in fiber optic gyros.

High-speed measurement at 1.5 sec/scan

Ideal for production applications

The Q8344A utilizes a Fourier spectroscopy system so that measurements can be completed in less than 1.5 seconds,

regardless of the measurement span and sensitivity (provided that the starting wavelength is 0.4 µm

or longer and that the measurement does not cover both short and long wavelengths).

The analyzer is therefore suitable for measuring laser diodes and light emitting diodes on production lines.

In addition, it can be used to evaluate the transmission and loss characteristics of optical fibers and filters.

When used as a system component, the analyzer can be triggered, measured,

and output data in just 1.5 seconds, dramatically increasing system throughput.

Wavelength measurement accuracy of ± 0.1 nm

Measurements are accurate to ± 0.1 nm (1.3 µm) using the built-in He-Ne laser as a reference light source.

As a result, accurate wavelength measurements can be made without wavelength calibration.

Maximum wavelength range of 0.05 nm

The Q8344A has a maximum resolution of 0.05 nm at short wavelengths (0.85 µm),

making it possible to measure CD and visible laser diodes in fully resolved oscillation mode, one by one.

Large-diameter fiber input (option)

An optional 200 µm large aperture input is available.

This option is required when analyzing devices with wavelengths larger than the standard fiber aperture (GI 50 µm).

For laser diode analysis, the standard 50 µm size is recommended,

while for LED analysis, this optional size is recommended.