Video Tour

High Performance LONG WAVELENGTH
The AQ6375 is the first bench-top optical spectrum analyzer covering the long wavelengths over 2 μm.
It is designed for researchers and engineers who have been struggling with inadequate test equipment to measure in these long wavelength ranges. The AQ6375 achieves high speed measurements with high accuracy, resolution and sensitivity, even while providing full analysis features. Troublesome calibration steps and the development of external analysis software is no longer required.

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The features of this AQ6375 are indispensable to the research, development, and manufacturing of optical devices in the wavelength range from telecom band to 2.4 um. No other test system can achieve this high performance and ease of use at the same time.

  •             Long wavelength measurement capability
  •             High wavelength accuracy & resolution
  •             High sensitivity
  •             High speed measurement
  •             USB for mouse, keyboard, and memory
  •             Remote operation (GP-IB, RS-232, Ethernet)
  • Optical fiber communications
  • Laser and optical device test
    • For gas sensing
      • medical
      • free-space communications
  • Passive optical devices

Long Wavelength 1200 nm to 2400 nm

The AQ6375 covers not only telecommunication wavelengths, but also the long wavelength region which is used for environmental sensing, medical, and industrial material applications.

High Sensitivity +20 dBm to -70 dBm

The AQ6375 can measure optical power as low as -70 dBm, which enables measurements of low power sources or low power output of a device under test.Measurement sensitivity can be chosen from seven categories according to test applications and measurement speed requirements.

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The spectrum of a white light source (yellow) and the background noise of AQ6375 (red)

High Resolution & Wide Dynamic Range

The AQ6375 uses a double-pass monochromator structure to achieve high wavelength resolution (0.05 nm) and wide close-in dynamic range (55 dB). Thus, closely allocated signals and noise can be separately measured.

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Measured HeNe Laser (1523 nm), Close-in Dynamic range: @ peak±0.8 nm

High speed Measurement


High Speed Sweep
With a proprietary sweep technique the AQ6375 achieves a much faster sweep speed than conventional measurement systems which use a monochromator. Max. sweep time is only 0.5 sec. in 100 nm span.

Fast Command Processing and Data Transfer
Applying a fast microprocessor, the AQ6375 achieves very fast command processing speed and Ethernet provides up to 100 times faster data transfer speed than the GP-IB.

Measurement Examples

1800nm DFB-LD
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Resolution: 50 pm, Span: 10 nm
Sensitivity: HiGH1/CHOP
2010nm DFB-LD
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Resolution: 50 pm, Span: 20 nm
Sensitivity: HiGH1/CHOP

Free-Space Optical Input


Applicable fiber: SMF and MMF

The AQ6375 uses a free space input structure, not having an optical fiber inside the monochromator, that can handle both single mode and multimode fibers. The free space input is also beneficial for measurement repeatability.

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Built-in Calibrator


The AQ6375 comes with a built-in calibrator for wavelength calibration and optical alignment adjustment of the monochromator in order to maintain accurate measurements. The calibration and adjustment are automatically performed and completed within a couple of minutes.

Wavelength Calibration

Calibrates with the designate absorption line of Acetylene gas.

Optical Alignment Adjustment

Corrects mechanical movements inside the monochromator caused by shock and vibration.

Note: the wavelength can also be calibrated with an external light source.

Building Automated Test Systems


The AQ6375 is equipped with GP-IB, RS-232, and Ethernet (10/100Base-T) interfaces to be connected with an external PC for remote access and building an automated test system. Macro Program is a useful built-in function for making a simple auto test program.

The standard remote commands of the AQ6375 are compatible with SCPI, which is an ASCII text based standard code and format that conforms to IEEE- 488.2.

The AQ6375 supports private remote programming codes of Yokogawa's best selling AQ6317 series for users to easily upgrade from their current automated test environment. (Note. some commands may not be compatible due to changes in specifications and functions.)


Macro programming enables user to easily create test procedures by recording the user's actual key strokes and parameter selections. An external PC is not required because the macro program can also control external equipment through the remote interfaces.
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LabVIEW® DRIVER available

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Optical and Electrical Connections



The AQ6375 adopts user replaceable optical connector for optical input and calibration output, enabling direct coupling to major optical connector types.

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AQ6375 Viewer - Emulation and Remote Control Software (Optional)

AQ6375Viewer is PC application software designed to work with Yokogawa's AQ6375 Optical Spectrum Analyzer.

The software has exactly the same user interface and functions as the AQ6375 so that you can easily display and analyze waveform data.

Allows to control AQ6375 from anywhere on the Ethernet network. Because of fast data transfer speed of Ethernet, measurement data can be updated in real time.

Note. the data update speed varies depending on network performance and conditions.

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Name Description File Type  
Bulletin AQ6370SR-10EN AQ6370 Series Optical Spectrum Analyzer pdf icon
2.77 MB
Name Description  
AQ6370 Viewer (learn more) Dedicated Viewer for Quick and Effortless Optical Spectrum Measurement Analysis Learn More
LabVIEW Drivers for AQ6370/AQ6373/AQ6375/AQ6370B/AQ6370C LabVIEW drivers for AQ6370/AQ6373/AQ6375/AQ6370B/AQ6370C y-Link

NA Conversion Adapter

NA Conversion Adapter

The 735383-A001 and A002 are unique adapters that reduces the numerical aperture (NA) of a connected fiber to half and is only applicable to the free space optical input structure on the Yokogawa AQ6370 series optical spectrum analyzers


All Products Guide
All Products Guide
PDF (8.40 MB)
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