Twenty-five years at Xerox PARC

In September 1970, in a secluded building nestled among the hills and horse ranches just west of Stanford University (Palo Alto, CA), a select group of scientists from around the world was assembled and charged with a mission: to invent the future (see photo). For Xerox Corporation, which had constructed the state-of-the-art facility known as Xerox PARC (Xerox Palo Alto Research Center), the goal was to create the office of the future by developing the technology that would be used there. In addition, by investing in basic research, the copier company felt it could not only enhance product quality and market share but also move into several new markets—particularly computers (see “Displays also developed at PARC”).

For the elite group of 23 that comprised Xerox PARC’s first research team, however, the meaning was much more literal: one day, they believed, millions of people would have access to desktop computers. These computers would be linked via high-speed, local-area networks (LANs), and those who used them would learn to think and communicate in revolutionary ways. The place that would make this happen was Xerox PARC.

“The breadth and amount of work that was accomplished during the 1970s and early 1980s [at PARC] was pretty incredible, and it was primarily a result of the people they hired,” says Don Scifres, who managed PARC’s laser and optoelectronics projects from 1972 to 1983 and who today is CEO of SDL (San Jose, CA), PARC’s first commercial spin-off. “Because the facility was new and there was no infrastructure in place, management let us follow our instincts. People who do that tend to accomplish a lot more than those who are told what to do,” says Scifres.

Although Xerox had its sights set on the commercial computer market, PARC quickly made its mark in personal computing. Among other things, PARC researchers are credited with inventing the first PC (the Alto), the first graphical user interface, the first laser printer, the first LAN (Ethernet), and the first object-oriented programming language. But, except for the laser printer, Xerox stumbled in commercializing these technologies and sat numbly by as young companies such as Apple and Microsoft made millions off ideas that had originated at PARC.

First diode lasers

Eventually, though, the company learned from its mistakes. Throughout the 1970s and early 1980s, as PARC’s computer-science accomplishments mounted, the electronic materials group—which is responsible for PARC’s laser and optoelectronics research—reached several milestones of its own. Under the direction of Scifres and two colleagues—Bill Streifer and Bob Burnham—these included a high-temperature, edge-emitting diode laser (1972), a distributed-feedback laser (1974), a buried heterostructure laser (1975), a phase-locked diode-laser array (1978), a MOCVD diode laser (1980), and a CW phase-locked diode-laser array (1982).

“The 1970s were a time when we were developing a brand-new technology,” says G. A. Neville Connell, manager of PARC’s Electronic Materials Laboratory. Among the initial applications for this technology were optical-recording systems and laser printers. PARC had developed laser printing in 1973-1974 using gas lasers, but realized that to make the printers commercially viable, a less-expensive, more-reliable laser source was needed.

Diode lasers looked promising. “But in those days, most of the developments were in the area of gain-guided lasers, which don’t have very good properties for laser printing,” Connell explains. Fortunately, index-guided laser technology, which has better printing properties, was also improving—so much so that Xerox was soon able to incorporate these lasers into its printers.

In fact, by the early 1980s, Scifres’ group had achieved such excellent results with high-power diode lasers and diode arrays that Xerox found itself at a crossroads: taking its printer technology to market would require a significant investment, in addition to a separate commercial entity to maintain access to that technology. Thus, in 1983, Xerox and Spectra-Physics (Mountain View, CA) established Spectra Diode Labs (known today as SDL), with Scifres at the helm.

“Having a commercial arm available also assisted us in moving diode-laser technology into Xerox products,” says Ross Bringans, manager of PARC’s semiconductor laser materials and devices group. “We needed a manufacturing capability for the components, and SDL was a key step in that effort.”

In 1992, SDL employees acquired Xerox’s interest in the company, but the two firms continued to work together. Today, SDL and Xerox PARC are involved in two joint projects: an ARPA contract for blue-diode-laser research and an Advanced Technology Program contract to develop multiple-wavelength diode-laser arrays.

“We believe there is a large market opportunity in color printing, so we are exploring ways to do that more efficiently,” Bringans says. “Using lasers of different wavelengths is one approach.”

Looking to new markets

After the formation of SDL, laser research at PARC shifted away from development of high-power diode lasers toward laser designs that today are helping Xerox create innovative printer architectures. In the electronic materials laboratory, some 20 researchers are now devoted to developing diode-laser prototypes for use in Xerox products.

“We look for ways to create lasers that make it possible to print at greater speeds and higher volumes and with better quality,” Bringans says. “This allows us to break into markets that previously were not open to us.”

For the last ten years, PARC’s laser research has centered on the development of separately addressable arrays and processing techniques (such as impurity-induced layer disordering), with the goal of enabling laser printing of 40 and more pages per minute (ppm). In 1989, work began on the AlGaInP materials comprising red diode lasers, which are used in high-performance laser printing.

As an outgrowth of this work, diode lasers with two separately addressable beams at a close beam-to-beam spacing were developed. According to Bringans, when placed in a laser printer, these devices simultaneously scan two lines of pixels, thereby doubling the print speed but maintaining a compact design.

“The more lasers you have, the faster you can print,” Bringans says. “So a lot of our work has been creating arrays of lasers. There is also a huge amount of interplay between the printer and the optical design, so we have customized the optical design as well. The outcome is higher-speed printing from a machine that is still compact and relatively inexpensive.”

Among other things, this technology is enabling Xerox to enter the mid- to high-end printing market. “High-end laser printing, which right now is at 135 ppm, is used for short-run documents for which it is more cost-effective to print 1000 documents on demand than to use a printing press,” Connell says. “Thus, our new laser arrays will allow Xerox to further move into a market traditionally held by the printing press.”

This same technology is also central to two new office-based products developed by Xerox: a 30-ppm networked printer for distributed printing that uses Xerox’s DualSpot lasers, and a scanner-printer-copier system known as the Xerox Document Centre. Xerox is projecting annual revenues of $1 billion for the Document Centre alone—a figure many analysts are calling “reasonable.”

Several Xerox competitors—including Canon, Ricoh, and Minolta—reportedly plan to introduce similar products; this time, however, thanks to the folks at Xerox PARC, these companies will have to jockey for second place.