- Yokogawa’s AQ6375E and AQ6376E optical spectrum analyzers combine near- and mid-infrared to measure a wide range of wavelengths.
- These instruments are aimed at meeting new needs in optical product development and manufacturing as well as laser characterization.
Yokogawa’s AQ6375E and AQ6376E are diffraction grating-based optical spectrum analyzers that cover SWIR (Short-Wavelength InfraRed) beyond 2 μm and MWIR (Mid-Wavelength InfraRed) beyond 3 μm.
These optical spectrum analyzers are offered in four versions providing distinct spectral coverage depending on the type of application being addressed.
The AQ6375E Standard offers a wavelength range from 1200 to 2400nm. The AQ6375E Extended Band version offers a wider wavelength range of 1000-2500nm and finally the AQ6375E Limited version has a wavelength range of 1200-2400nm (with lower optical resolution). The AQ6376E Standard offers a spectral coverage from 1500 to 3400nm.
In the field of environmental measurement and gas detection, the AQ637xE can be used to measure gas absorption spectra and characterize light sources used in laser absorption spectroscopy.
These optical spectrum analyzers can be used in the development and measurement of lasers, characterization of broadband light sources such as Supercontinuum sources, as well as passive optical devices and optical fibers.
The AQ637xE features a free-space optical input that allows both single-mode and multi-mode (up to 400 µm) optical fibers to be used on the same analyzer for both SWIR and MWIR regions. The small variation in insertion loss at the input connector increases measurement repeatability, while the lack of physical contact with the ferrules of the optical connectors of the connected fibers prevents damage to them.
An integrated optical source allows both optical alignment and wavelength calibration to be performed automatically. This maintains optical performance by compensating for optical axis deviation caused by vibration and wavelength deviation caused by changes in ambient temperature.
The AQ637xE also uses an air purge function to compensate for another possible cause of error. In the SWIR and MWIR regions, there are wavelengths where the light has strong absorptions due to the presence of water vapor and carbon dioxide, both of which can interfere with the spectral measurement.
By continuously injecting a pure purge gas, such as nitrogen, into the monochromator (via dedicated connectors on the rear panel), the AQ637xE can reduce the influence of light absorptions on the measurement.
High-order diffracted light is also compensated for by a built-in cutoff filter in all versions except the limited model AQ6375E-01. This is necessary because the monochromator generates high-order diffracted light, whose wavelengths are equal to integer multiples of the input wavelength. The built-in filters reduce this high-order diffracted light, minimizing its influence on the accuracy of the measurement.
To analyze the results, the AQ637xE has built-in analysis functions to characterize the optical spectra of a wide variety of optical systems and devices, such as WDM, DFB-LD, EDFA and optical filters.
Analysis functions include: DFB-LD; FP-LD; LED; spectral width measurement (peak/notch); SMSR; optical power; WDM (OSNR); EDFA (Gain and NF); filter (peak/bottom) and WDM filter (peak/bottom).
To improve measurement efficiency and productivity, the AQ637xE features an application mode (APP), which turns the optical spectrum analyzer into a versatile instrument dedicated to the device under test (DUT).
The APP mode provides a specific user interface for the DUT that allows the user to switch between configuration parameters and test results without needing to know the wide variety of analyzer parameter settings. The AQ637xE comes preinstalled with several basic applications such as WDM test, DFB-LD test and FP-LD test. A wizard guides the user through a configuration process for specific measurements and analysis.
Additional test applications will be available for download from the Yokogawa website and can be added to the AQ637xE through future software updates.
The AQ637xE series optical spectrum analyzers feature a high-resolution 10.4-inch LCD (capacitive multi-touch) touch screen. Users can change measurement parameters, perform analysis and change the optical spectrum view just like on a touchscreen tablet.
Ergonomics are further enhanced by the addition of frequently used keys to the hardware keys on the front panel. These include keys for scan control (Auto/Single/Repeat/Stop), optical resolution adjustment and sensitivity adjustment.
The AQ637xE also has USB ports that support USB storage devices, mice and keyboards. Data and screenshots can be saved to the internal memory or to a USB memory stick to create test reports, while connecting a mouse or keyboard to the USB port allows the AQ637xE to be used in the same way as a PC.
The standard network (LAN) port allows access to files stored in the internal memory and remote software updates from a PC. The APP function also supports a fiber optic inspection probe, allowing users to view the quality of the surface condition of the optical connector.