Yokogawa’s AQ6380 OSA sets new performance standards

The optical spectrum analyzer (OSA) has been a mainstay instrument since photonics and optoelectronics first began transforming high speed digital communications. The experts at Yokogawa delve into highlights of their class-leading AQ6380 in a discussion with the company’s European marketing manager.

BY KELVIN HAGEBEUK, PRECISION MAKER, MARKETING MANAGER -TEST & MEASUREMENT, YOKOGAWA EUROPE B.V. and Mark Andrews, Editor of PIC Magazine

MA: Optical spectrum analyzers are essential to any advanced photonics R&D or product development work. Can you update us concerning Yokogawa’s role in the industry and what led to the AQ6380?

YOKOGAWA: For decades, the Optical Spectrum Analyzer (OSA) has been a workhorse in the R&D labs of telecommunications and networking equipment and component manufacturers. These companies use OSAs to characterize cables, components and systems for fiber optic communications applications. With this field in mind, the Yokogawa AQ6380 offers the leading optical performance required by engineers and scientists as they develop and improve the speed, bandwidth and quality of the optical devices used in the next generation of telecommunication networks.

Yokogawa has been developing OSAs since 1980 and now offers eight models. These OSAs cover a wide range of wavelengths, from the visible light spectrum to the mid-wavelength infrared region.

This range of wavelengths is needed because as well as testing telecommunications components, they are also increasingly used for precision measurement in the fields of industrial production, bio-photonics and healthcare, LED lighting, quantum computing and environmental sensing. These trending application areas have all led to a demand for greater wavelength range. OSAs are key instruments for scientific researchers who appreciate the superior performance of Yokogawa’s rotating grating technology compared to other measurement instruments such as spectrometers. In all these applications, our customers prize the precision and sensitivity of Yokogawa’s spectrum analyzers.

MA: The spectral resolution of the new analyzer appears to represent a real leap in performance. Can you describe the highlights of key factors that contribute to this achievement?

YOKOGAWA: Our new monochromator, which forms the heart of the OSA, has been completely redesigned and has sharper spectral characteristics than ever before. It ensures the AQ6380 can offer an excellent optical wavelength resolution of up to 5 pico-meters. This means that optical signals in close-proximity, such as different DWDM-channels or different spectral components found in lasers, can be clearly separated.

This resolution is required because growing traffic leads to networks using more power, which also causes increased carbon emissions. One approach to cutting energy use is to utilize networks more efficiently, getting more data through the same cable. High capacity optical backhaul networks will be needed to serve this growing traffic density, so developers need to distinguish different frequencies more clearly. Another stand-out quality of the AQ6380 is the fact this new instrument offers 0.005 nm wavelength resolution, four times better than the AQ6370D-22’s figure of 0.02nm. With the AQ6380, waveforms that were previously not even visible, such as modulation side peaks in the laser spectrum, can now be accurately visualized.

MA: How does this new analyzer compare to competing solutions?

YOKOGAWA: The AQ6380 offers the leading optical performance that engineers and scientists need to develop and improve the speed, bandwidth and quality of optical devices used in the next generation of telecommunication networks.

The AQ6380 is the world’s best grating based OSA, so it is second to none. It outperforms other suppliers’ OSAs by wavelength accuracy, resolution, dynamic range, and actual measurement speed. There isn’t really another OSA on the market that offers this combination of competing specifications. The instrument that comes closest is Yokogawa’s own high-performance AQ6370D-22.

MA: What can the AQ6380 do for PICs that other analyzers can’t do as well?

YOKOGAWA: Future bandwidth requirements push the performance of DWDM systems. As a result, the telecommunication channels of optical transceivers become ever more closely spaced, making it a challenge for the OSA to separate the individual channels.

When testing PICs used in WDM transmission systems, high spectral measurement performance is required to test the system’s internal circuit boards, including laser modules and optical transceivers.

Testing these optical components requires high accuracy. Applications may include modulated signal measurement of optical transceivers and transponders and measurement of all WDM channels of optical transceivers beyond 100G.

The AQ6380’s high resolution and wide close-in dynamic range allows accurate OSNR measurement, while the built-in WDM analysis function analyzes the measured waveform and shows peak wavelength, peak level, and OSNR up to 1024 channels simultaneously.

The AQ6380’s SHARP spectral characteristics and high stray-light suppression performance enable developers to visualize and accurately measure spectral peaks that are very close together.

MA: In comparing how the AQ6380 operates alongside other members of the Yokogawa lineup, or comparing it to competing analyzers, how easy is it to get started and use the AQ6380 on a daily basis?

YOKOGAWA: The new AQ6380 is designed for ease and efficiency of use, ensuring the measurement scheme can be set up rapidly and data can be acquired easily.
The high-resolution, responsive 10.4-inch touchscreen LCD makes the device as easy and intuitive to operate as a tablet. When it comes to analyzing results, the AQ6380 has built-in analysis functions to characterize optical spectrum from a variety of optical systems and devices, such as WDM system, DFB-LD, EDFA, and filters.

Analysis functions include: DFB-LD; FP-LD; LED; Spectral width (peak/notch); SMSR; Optical power; WDM (OSNR); EDFA (Gain and NF); Filter (peak/bottom) and WDM filter (peak/bottom). With a few button presses, all information is available on the display. The AQ6380 also features an application menu known as “APP mode”, which makes measurement set-up much easier. It is much like using a smart-phone or tablet. Pushing the APP button brings up an overview of the pre-installed testing apps – WDM, DFB-LD, FP-LD and LED testing. A guide through wizard leads the user through an easy set-up process for specific measurements and analysis.

New or additional testing applications will be made available to customers for download from the Yokogawa website and can be added to the AQ6380 by future firmware updates.

The AQ6380 achieves a wavelength resolution of 5 pm. It enables the separation of closely allocated DWDM channels and modulation side peaks of optical transceivers, which were not visible with previous models.

MA: Yokogawa’s analyzers are known for quality. How does the value proposition work when a researcher needs to convince her department to make a new investment?

YOKOGAWA: The AQ6380 is not a basic analyzer - it’s the world’s best grating based OSA, so it is second to none. It’s an extreme precision Optical Spectrum Analyzer that features improved precision for developing and producing the next generation of optical network backhaul components.

Moreover, Yokogawa instruments are renowned for maintaining high levels of precision and for continuing to deliver value for far longer than the typical shelf-life of such equipment. Yokogawa believes that precise and effective measurement lies at the heart of successful innovation. The company has focused its own R&D on providing the tools that researchers and engineers need to address challenges great and small.

One other benefit is the ability to emulate the OSA on a PC and control it remotely with the ‘OSA Viewer’ application software. OSA Viewer’s user interface and analysis capabilities allow R&D and production users to easily view and analyze waveforms on their PC or laptop.

The AQ6380 can be controlled remotely via a direct connection or over a network. An automated measurement system can be readily built with a remote-control interface using either Ethernet or GP-IB. The remote command set conforms to the Standard Commands for Programmable Instruments (SCPI). Other Yokogawa OSAs use the same command set, which is compatible with AQ6370 series and AQ6319, as well as proprietary AQ6317-compatible commands.

These features are ideal when R&D users need to evaluate and analyze measurement data, optimize test conditions and troubleshoot on remote lines, and when production users need to collect and analyze measurement results from remote production lines.

Modulated spectrum of 10G optical transceiver

MA: What characteristics translate most readily into benefits the researcher will appreciate?

YOKOGAWA: Excellent optical wavelength resolution of 5 pm allow optical signals in close proximity to be clearly separated. This is a key capability.

MA: Yokogawa products are second to none. What else sets the company apart from competitors, especially in light of the challenges we face in recovering from a global pandemic?

YOKOGAWA: At Yokogawa Test & Measurement, we provide more than simply products. We provide lasting value to customers. Our diverse and comprehensive range of solutions and services mean we are constantly working closely with our customers. Yokogawa believes that precise and effective measurement lies at the heart of successful innovation – and has focused its own R&D on providing the tools that researchers and engineers need to address challenges great and small.

One of the essential aspects of maintaining the accuracy of an OSA is regular calibration to known standards. The AQ6380 employs on-board calibration through a built-in light source. Calibration of the wavelength is performed automatically at set intervals by switching the optical path with an internal optical switch. Yokogawa instruments are renowned for maintaining high levels of precision and for continuing to deliver value for far longer than the typical shelf-life of such equipment. Purchasing an OSA from Yokogawa is a future proof investment. For current Yokogawa OSA users, the AQ6380 is also backward compatible, making it easy to upgrade existing measurement systems.