Photodigm Lasers in the Supply Chain

John Spencer About The Author

Wed, Jul 03, 2013 @ 02:42 PM

Photodigm produces laser diodes in the technologically important near IR band, which covers multiple wavelengths of industrial and scientific interest.  It includes the spectroscopic transitions of O2, Rb, Cs, K, and metastable He, as well as the workhorse wavelengths 808, 980, and 1064 nm.   This also happens to be where many consumer applications of lasers exist, such as CDs, DVDs, laser printers, and motion sensing devices.  As is typical for many optical applications, scientific, industrial, and consumer lasers offer little overlap in performance requirements.   For a number of years, for example, Laser Focus World reported that 780 nm lasers, used for CD players, were the single largest volume selling laser diode by wavelength.  By power, 808 nm devices for pumping solid state lasers are the leaders.  Between requirements for power and consumer applications, not to mention the huge telecom market, the tiny volume of devices required for scientific lasers was almost a rounding error and given minimal attention by major laser diode manufacturers.  SDL supplied early versions of scientific diodes in the 1990’s, but their interest was overwhelmed by the telecom bubble.  Without reliable access to precision diodes,  scientific laser systems suppliers were able to meet market needs by creatively repurposing consumer or industrial devices.  While the requirements of consumer and scientific products did not totally overlap, diode laser systems manufacturers were quite happy to forage devices from this large scale production and build their systems around them. Tunable external cavity diode lasers (ECDLs) of adequate performance could be produced from these readily available chips, satisfying a growing scientific market.  It was not easy -- often consumer devices had to be remanufactured to make them suitable for the new application. Japanese electronics manufacturers Hitachi, Sony, and Sanyo dominated the consumer market and made no attempt to produce devices optimized for precision applications.  However, the high volume of lasers used for these consumer devices ensured production and availability of usable devices across the band. 

Such was the state of the art in 2008 when Photodigm introduced its first 780 nm DBR laser products specifically designed for Rb spectroscopy.   We immediately learned that the market was ready for a high performance laser supplier who specialized in precision devices.  Power, reliability, and robustness were required to ensure the advancement of the technology from science experiment to fielded product.    Our customers quickly realized the inherent advantages and robustness of the monolithic DBR architecture.  They also came to realize that progress in their programs required a specialized and focused supply chain.  The changing nature of the consumer electronics market also resulted in the strategic exit of the large manufacturers from the laser business.  Even the manufacturers of ECDLs came to realize that their comfortable existence as “parasites on the tail of the consumer supply chain” (quoting a private source in the industry) was threatened.  Suddenly, the supply of semiconductor gain media became critical and was viewed as a key strategic resource.   The laser supply chain as taught in the Britney Spears School of Electrical Engineering no longer existed, if it ever did.(1)

Photodigm supports the market and our customers by careful attention to detail.  Photodigm works with many laser systems manufacturers.  However, the heart of the laser system is the gain medium, whether it is a DBR, FP, or SOA.   Controlling our own fab means that we can focus our resources on exactly what is necessary to produce a high performance product.  Make no mistake about it.  Making precision DBR lasers requires extreme attention to detail of the key elements -- epi design, gain ridge, wavelength selection elements, and facets.   It also means that we can offer timely response as customer applications evolve. From two wavelengths in 2008 -- 1083 and 780 nm -- Photodigm has expanded its product line to over 20 wavelengths today, and we are continuing to expand the line -- within the last few months we have broadened our product offerings with the world’s highest power single frequency 780 and 852 nm diode lasers, introduced a new TOSA package designed to handle the higher heat loads of these devices, and added a new wavelength (805 nm) to our DBR line.  Furthermore, the high performance single mode ridges that characterize Photodigm single frequency DBR lasers are now available in specialized gain chips with custom facet coatings for high performance widely tunable ECDLs. As a result of these developments, Photodigm lasers and gain chips are entering the supply chain in multiple places, and they will be found in many newly introduced OEM products over the next year.  

Since it all depends on the gain medium, please contact us for further information regarding our high performance monolithic DBR lasers and SAF gain chips.  


(1)  According to the Britney Spears School of Electrical Engineering, electricity comes from the wall outlet, and high performance lasers can be bought from multiple sources off the Internet.  


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