Advantest Q8340 Series
3 models with full specifications from Advantest.
The Advantest Q8340 series, including the Q8341, Q8344A, and Q8347, consists of optical spectrum analyzers (OSAs) designed for high-resolution spectral and coherence measurements. Unlike conventional diffraction-grating instruments, these analyzers utilize a Fourier spectrum system based on a Michelson interferometer. This design enables direct assessment of optical coherence length and delivers excellent wavelength resolution. Depending on the model, these instruments are optimized for evaluating Wavelength Division Multiplexing (WDM) systems, characterizing narrow-band optical filters, or measuring coherence in the short-wavelength spectrum. This page details the shared technology platform and outlines the specific operational parameters, wavelength ranges, and physical interfaces that distinguish each instrument.
- Measurement Principle
- Fourier spectrum system with Michelson interferometer
- Wavelength Range
- 350 nm to 1750 nm (model dependent)
- Internal Reference Laser
- He-Ne Laser (632.8 nm)
- Standard Interface
- GPIB (IEEE-488)
Models in this series
Technology and Measurement Principles
The common foundation of the Advantest Q8340 series is the Michelson interferometer-based Fourier spectrum design. This system provides a wider measurement span compared to conventional Fabry-Perot interferometer systems. To maintain high wavelength accuracy, the instruments employ an internal He-Ne laser operating at 632.8 nm as a reference source.
This architecture also enables the direct measurement of optical coherence length. This characteristic is valuable for optical system evaluation and component testing, particularly where conventional diffraction-type monochromator spectrometers cannot directly resolve coherence parameters.
Model Differentiation and Applications
Each model within the series is tailored to distinct spectral ranges and measurement tasks:
- Advantest Q8347: This model is optimized for telecom applications, spanning a wide wavelength range of 350 to 1750 nm. It is designed for evaluating WDM transmission systems, ultra-high-speed networks, and narrow-band optical filters. It provides high resolution of up to 0.001 nm at 1550 nm, a polarization dependence of $\le \pm0.1$ dB, and an optical dynamic range of 45 dB at $\pm0.2$ nm from the peak.
- Advantest Q8341: Operating within a 350 to 1000 nm range, this model is designed for high-resolution measurements, offering a wavelength resolution of 0.01 nm (or up to 1 pm / 1 GHz in frequency mode). It features a fast minimum sweep time of 0.5 s and supports direct coherence length measurements up to 40 mm.
- Advantest Q8344A: Designed specifically for the 350 nm to 1000 nm band, this instrument focuses on direct coherence length measurements and Fourier spectrum analysis using a Michelson interferometer.
Physical Characteristics and Connectivity
Connectivity and hardware options vary between generations. The Advantest Q8344A and Advantest Q8347 rely primarily on a GPIB (IEEE-488) interface for instrument control, while the Advantest Q8341 offers an expanded interface suite, including GPIB, VGA output, Centronics Parallel, a keyboard port, and an integrated 3.5-inch floppy disk drive (FDD) for local data storage.
Display formats also differ: the Q8344A utilizes a built-in CRT display, the Q8347 employs a color LCD, and the Q8341 features a 6.5-inch color TFT LCD. Physical ports for optical input are standardized on FC-PC (or FC/PC) connectors across the units. For bench placement, the Q8341 has dimensions of 424 (W) x 177 (H) x 450 (D) mm and weighs 15 kg.
Frequently asked questions
- Which model in the series supports the widest wavelength range?
- The Advantest Q8347 supports the widest wavelength range, covering 350 to 1750 nm, which makes it suitable for WDM and telecommunications testing.
- What is the maximum coherence length the Q8341 can measure?
- The Advantest Q8341 can measure coherence lengths up to 40 mm.
- What are the display technologies used in the different models?
- The Advantest Q8344A has a built-in CRT display, the Advantest Q8347 has a color LCD, and the Advantest Q8341 is equipped with a 6.5-inch color TFT LCD.