ISOZAKI Katsumi1
This paper summarizes the state of research in the field of photonics technology, specifically work related to photonic sensing technologies. For details on optical communication, refer to "Yokogawa Technical Report Vol. 52 No. 3 Photonics special issue." In this paper, we report a technique for measuring interference for optical components in next-generation optical communication, a unique tunable laser device that combines MEMS technology and compound semiconductor technology, a high-speed inline near infrared analyzer conforming to PAT (Process Automation Technology) proposed by FDA (Food and Drug Administration), and a detection technology for gene chips.
- Advanced Technology Research Center, Corporate R&D Headquarters
INTRODUCTION
Photonics development in Yokogawa's Corporate R&D Headquarters falls into two categories. One is work related to building backbone networks in rapidly expanding optical communications. We have developed 40-Gbps optical communications modules based on our proprietary high-speed, high-frequency compound semiconductor device technologies. Now that development and incubation work in the Corporate R&D have been completed, activities have been shifted to a newly formed optical communications division. Although we have only just entered this field, we have developed compound semiconductor devices based on our strongly differentiating technologies. The business is targeted at social infrastructure where we have much experiences, and so we expect optical communications to become a core new business. For details, refer to "Yokogawa Technical Report Vol. 52 No. 3 Photonics special issue" (2008, No. 46).
The other category is related to photonic sensing. Yokogawa, which has long been involved in the measurement industry, quickly recognized the value of the non-contact, noninvasive, high-speed, and high-sensitivity characteristics of photonic sensing. We have been actively providing optical measuring instruments, spectroscopic analyzers, and confocal scanners to the market by using our integrated photonic sensing technologies.
In both categories, we have common strategies for competing in the market using our strengths in social infrastructure and commercializing products based on our differentiating technologies, particularly optical devices. In this paper, we introduce our activities and recent developments in each instrumentation technology for optical applications.
OPTICAL MEASURING INSTRUMENTS
We are focusing on optical measuring instruments in the measurement industry. Following the merger with ANDO Electric, we obtained technologies on basic optical measuring instruments such as optical power meters, optical spectrum analyzers, optical time domain reflectometers (OTDR), tunable laser optical sources, and sensing instruments such as fiber sensors. The merger brought together the technologies of the two companies, and gave birth to measuring instruments for optical communications including wavelength monitors for dense wavelength division multiplexing (DWDM) and 40- Gbps bit error rate tester (BERT) systems. Optical measuring instruments are based on technologies to generate light, and technologies to detect light. In this section, we introduce our activities in these areas.
Developing interference measuring technologies
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| Figure 1 Optical system for interference measurement |
In the next-generation optical network, faster transmission speeds mean that transmission quality is largely dependent on the dispersing property of the parts. As a result, when developing optical parts, an optical network analyzer is needed to simultaneously measure the basic characteristics, insertion loss (IL), polarization dependent loss (PDL), group delay characteristic and polarization mode dispersion (PMD), at high speed. To do this, we have been developing interference measurement technologies. All parameters of an optical device can be measured simultaneously from the interference signals obtained by irradiating the measuring parts of the device under test (DUT) with the light from a tunable laser optical source and sweeping its wavelength continuously. Figure 1 shows the optical system for interference measurement under development.
Developing a tunable surface-emitting laser optical source
A small, inexpensive laser optical source, which can freely change the wavelength of light with a high spectrum purity, like a synthesizer of electronic measuring instruments, will not only greatly affect the sensing industry but may also serve as the optical source for next-generation optical communications and medical diagnosis. Figure 2 shows a photograph of the tunable surface emitting laser optical source under development. This device has a unique structure that combines MEMS technology and compound semiconductor technology which are our differentiating technologies. For details, refer to "High speed micro-mechanically tunable Surface Emitting Laser with Si-MEMS technology" in this Yokogawa Technical Report.
SPECTROSCOPIC ANALYZER
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| Figure 2 Tunable surface emitting laser optical source |
Yokogawa provides systems that quantitatively visualize the demands and issues in the social infrastructure by using measuring and modeling technologies, and that respond to such demands and issues with control technologies. Since many customers require a sensing technology that measures and controls quantities in-line that had not previously been visualized, the Corporate R&D has developed fundamental technologies for the NR800, a Fourier transform (FT) type near-infrared spectroscopic analyzer, which has now been commercialized. This concept is expected to be introduced into the pharmaceutical industry where inefficient batch production systems are dominant, and the US Food and Drug Administration (FDA) is advocating process automation technology (PAT). In response, the Corporate R&D has been developing a near-infrared spectroscopic analyzer that conforms to PAT. This analyzer features capabilities such as measurement of powder and high-speed measurement. Its unique technology is a photo-diode array (PDA) of a 640-element compound semiconductor which is manufactured in our compound semiconductor manufacturing facility. Based on this key device, together with the optical technologies we have developed for optical measuring instruments, we created a small high-speed near-infrared spectroscopic analyzer which has no moving parts and conforms to PAT. For details, refer to "High-speed in-line use spectrometer using a highly integrated original array sensor" in this Yokogawa Technical Report.
APPLICATION OF CONFOCAL MICROSCOPE IN BIOTECHNOLOGY
In 1996, Yokogawa released a confocal microscope for measuring living cells which produces fluorescent images with low noise at high speed (more than 1,000 frames/s), ushering in a new era in the life science field. This microscope features a unique scanning technology that increases the signal light and decreases noise light simultaneously by combining a Nipkow disc with a micro-lens array, a remarkable integration of micro-technology and optical application measurement technologies. Incorporating a confocal scanner unit as a differentiating module, we are now developing a high- throughput screening system for drug discovery1 and a DNA chip reader for personalized medicine. For details of the DNA chip reader, refer to "Gene measuring system for safe and reliable diagnoses" in this Yokogawa Technical Report.
CONCLUSION
Yokogawa's Corporate R&D operates a successful business model in which it develops various differentiating devices, uses them in a variety of applications, and provides customers with unique advantages. The paper on the tunable surface-emitting laser optical source in this report describes how we developed the new differentiating device, while another paper on the high-speed in-line spectrometer shows how we evolve and apply differentiating technologies into new applications.
REFERENCE
- Takayuki Kei, Taichiro Nezu, et al., "Elemental Technologies for Genome-based Drug Discovery Test System Using Cultured Live Cells," Yokogawa Technical Report English Edition, No. 45, 2008, pp. 27-30