All companies, but especially those in technology, like few things better than to talk about their "breakthroughs," those great leaps forward that make products out of the formerly impossible. A search by Factiva Consulting Services found that more than 8,600 press releases have been issued over the years with "breakthrough" in the headline, a majority of them by computer and electronics companies.

IBM, incidentally, is the year's breakthrough champion, at least in terms of how often it has headlined the word in its press releases. The company has had eight headline-worthy breakthroughs since January in customer privacy, energy efficiency, speedy billing software, storage, mainframes (twice), computer networking and voice recognition.

But to what extent are we experiencing "breakthrough inflation," in which the work that an engineer would consider simply a good day in the lab becomes, in the hands of the PR department, an advance worthy of being shouted about from the rooftops?

A breakthrough-themed announcement from one of the biggest Silicon Valley companies shows some of the issues involved in evaluating whether a particular technical development merits "breakthrough" status.

It was issued this month by Intel, and it involves optical computing -- that is, using light rather than electrons to transmit digital data. Optical communications are already used throughout the fiber strands of our phone networks, but the electronic devices that make them possible are much too expensive for the insides of a desktop PC, or even for the high-end servers used by businesses.

Intel has been working to change that, and it has announced a number of optically oriented breakthroughs in recent years. The theme of all of them has been finding ways to use ordinary low-cost silicon chips to manipulate the laser light used in optical computing.

Intel's latest breakthrough involves, of all things, glue -- specifically, finding a way to attach a layer of indium phosphide, a material long used to generate photons in laser equipment, to the top of a piece of silicon. That step had eluded researchers for years. With it accomplished, you get the breakthrough of a "laser on a chip."

Intel says the arrival of such a laser chip will hasten the arrival of the day when, for instance, the different parts of your computer will communicate via laser fibers instead of copper wires. (Light travels farther and generates less "noise" than electrons running over copper.)

It will also allow, says Intel, different parts of a computer -- the microprocessor and memory, for instance -- to be much farther apart than they are today, including on the other side of the room from each other. That would help diffuse the heat generated by the rows and rows of servers now found in the computer rooms of even medium-sized businesses. In turn, that could result in lower energy costs. Nearly every big company these days says that the biggest problem its IT shop has is getting enough power to run all the computers the company is buying.

Having been inside Intel's laser labs, I need no persuading that the company is doing important work here, and an Intel spokesman says the development is indeed a "breakthrough" because it shows how real-world optical products can be made with silicon. I wonder, though, how many more breakthroughs we will be reading about before optical computing becomes ubiquitous. An Intel spokesman says the laser chip is indeed a "breakthrough" because it shows how real-world optical products can be made with silicon.

But being a "breakthrough" implies that you don't need a lot more like it to get to where you need to go. Intel is the first to admit that many issues remain to be solved before that day is at hand in this case -- including, for instance, getting the hybrid indium-phosphide and silicon chips to produce light at the high temperatures that are normal in computer parts. If every few months produces a breakthrough, we might want to change what we are calling it to something less arresting -- perhaps "research advance."

Like many other companies, Intel may also have a penchant for overclaiming even with well-grounded technical accomplishments. For example, the company said its recent work will hasten the arrival of ultrafast fiber Web connections to the home because silicon-based laser components will reduce the cost of optical networks.

True enough, but the real expense of fiber to the home is digging up sidewalks and front yards. Unless Intel is also working on silicon-based shoveling technology, that cost is not likely to come down any time soon.

There is another category of "breakthrough" in which the word becomes a synonym for a "supremely useful product." One example is Dtrace, a piece of software that is like a computer debugger on steroids.

Dtrace was developed by a team of engineers headed by Bryan Cantrill at Sun Microsystems, and earlier this month, it won first place in The Wall Street Journal's Technology Innovation Awards. It enables engineers to diagnose a computer and say how well it's running and what might be causing a program to hiccup -- all without interfering with the machine's operations.

If Dtrace won't change computing, it's at least available today. Not only is it currently shipping from Sun, it also has been licensed by Apple Computer for new versions of the Macintosh. Apple and Sun together: Now there's a breakthrough.