Welcome to Sam's Laser FAQ!

This collection of documents, called "Sam's Laser FAQ", has a great deal of practical information on a variety of laser related topics. If you are already familiar with its scope, purpose, and general organization, you can go directly to Sam's Laser FAQ Table of Contents. However, if this is your first visit - or you have been away for awhile - check out the summary and version update info below.

Sam's Laser FAQ provides a wealth of useful (not just textbook) information on many types of lasers of interest to the experimenter and hobbyist:

• Basic laser principles, laser safety, general laser information, laser instruments and applications, laser and parts sources, laser discussion groups and newsgroups, and many references, and links. There is even a list of laser experiments and projects. (The descriptions are somewhat sparse at the moment but there are also links to other related Web sites.)

• Diode, Helium-Neon (HeNe), Argon/Krypton (Ar/Kr) Ion, Carbon Dioxide (CO2), Helium-Cadmium (HeCd), and Pulsed and Diode Pumped Solid State (SS) laser characteristics, drive requirements, and power supply design considerations. Schematics for at least 25 diode laser drivers, 40 complete HeNe laser power supplies, 6 complete Ar/Kr ion laser power supplies, and 6 pulsed SS laser power supplies, as well as many other support circuits like regulators and modulators.

• Amateur laser construction (building lasers from raw materials rather than from laser components). Extensive material on getting started in this exciting and challenging pastime (often a great deal of time!) as well as complete descriptions - with diagrams - of the home-built lasers from the Scientific American "Amateur Scientist" columns (and the collection "Light and its Uses") and other sources.

Sam's Laser FAQ was developed to provide a unique resource for experimenters and hobbyists - as well as just plain old basement tinkerers. To the best of my knowledge, nothing as comprehensive has ever been available anywhere else in the explored universe (and almost certainly beyond) either on-line or in print.

If this was what you were looking for, your search is over! :-)

A Word About These Pages

In return for this gold mine of information, please make a serious effort to find the answers to your questions before contacting me. It may take just a wee bit of effort and could stress a few neurons in the process, but there is an excellent chance that what you seek is covered here. Should you be really stuck - or just want to discuss lasers, I will respond to email in a timely manner. However, if your questions indicate that you haven't even gotten past the Welcome Page, AND I am in a good mood, you will get a somewhat polite reply to read the appropriate chapter(s) of the FAQ. On the other hand, if it is a bad day, and you are really really lucky, you will probably be ignored. Don't get me wrong - I enjoy discussing lasers with laser enthusiasts and novices alike, and will be happy to do so at almost any hour of the day or night. However, if you're seeking some basic information, I would really really appreciate it if you do at least a bit of your homework first. In any case, if you do email me, I expect to be able to hit the reply key for my mail program and not get bounced email. I will not attempt to unjumble any anti-SPAM email addresses! I have posted over 20,000 articles to the USENET newsgroups using my true email address. And, you won't pick up SPAM via my private email anyhow. Even computer viruses avoid my address book since it's on a unix system!) Yes, SPAM is a pain but I tolerate the small amount I get resulting from postings so others will not be inconvenienced.

However, due to the increasing amount of SPAM via repairfaq.org email addresses, I have decided to require all initial email contact from the FAQs to be via the Feedback Form on the Sci.Electronics.Repair FAQ Email Links Page. (At some point my repairfaq.org email address will cease to function.) Any reply from me will have a valid email address to use for future correspondance. My apologies but I've already made so many millions from all those get rich quick schemes that I've run out of places to put it all. :)

Note: I NEVER send email attachments. If you receive a message supposedly from one of my addresses with any sort of attachment, it is bogus and possibly a virus - someone's address book includes my address and their computer is infected. Send me the complete headers and I'll attempt to check it out just hit the delete key.

Navigating Sam's Laser FAQ

Sam's Laser FAQ is divided into chapters and sections. Except for the introductory material including the Table of Contents (ToC), each chapter is a separate file and has its own Sub-Table of Contents (Sub-ToC) Anything smaller than a chapter is called a section and has its own header and link from the chapter's Sub-ToC. Multiple sections may be grouped where they are related to one topic or related topics. For the most part, there are no nested text files. With one or two possible exceptions, the only files below the text files are those for diagrams and photos. To minimize download time, there are no in-line graphics anywhere except the Laser Equipment Gallery where relaxation is encouraged. :)

Links to return to the ToC are located at the beginning of every chapter and links to return to its Sub-ToC (top of page) are located at the end of the chapter as well as between major sections. There is also a link at the end of every chapter to the next chapter.

Hyperlinks within the text will either be to other chapters or sections of Sam's Laser FAQ (in which case they will generally be preceded with "chapter:" or "section:" as appropriate) or to other pages on this Web site or elsewhere. All local links have complete URLs including the filename so it is possible to tell if the link is to some other page (if the filename doesn't match the one currently being read).

All of Sam's Laser FAQ uses the very simplest HTML. This is partly because I have to maintain it and partly to avoid fluff. :) I have thought about adding a framed entry point which would include the ToC(s) down the left edge and would be interested in any opinions you may have on this and other formatting issues.

I realize that a fast search facility would be really nice. Eventually, I may have one (I refuse to use free search engines that impose advertising. They tend to be too slow anyhow.) In the meantime, realize that you can always use Ctrl-F in your browser to search any single document. The two special files: Sam's Laser FAQ Expanded ToC and Sam's Laser FAQ Comprehensive Table of Contents provide a means of using this technique to find desired topics with a minimum of effort. You can also use the search engine on the Drexel S.E.R FAQ Mirror Site. However, if someone would offer to provide a fast non-commercial search engine that I can just drop in with near zero effort, please contact me me via the Sci.Electronics.Repair FAQ Email Links Page.

Sam's Laser FAQ Sites

The mirror sites (no pun intended... OK, well maybe just a little one-sided one) will always maintain a reasonably current version of this document. Check the individual sites for the latest version and specific viewing and download options and try to use the site nearest you to minimize Web traffic!

There is also an early version (even predates the name "Sam's Laser FAQ") at The Laser Resource Library which is quite ancient (and ugly) at this point. I have no plans to update it mainly because I have lost the password and become disgusted with the annoying advertising imposed by the operators of that site. :-) Or, go to Sam's Laser FAQ Archive for this and a couple other antiques.

We are always looking for contributions (of all types) in any and all laser related areas to expand the content of these sites.

Version Update Information

What's New as of V6.60

• The information on specific solid state lasers has been greatly expanded especially for the Coherent C315M and addition of the JDS Uniphase uGreen in the chapters: Solid State Lasers and SS Laser Testing, Adjustment, Repair.

• The principles of the Scanning Fabry-Perot Interferometer are discussed in the chapter: Laser Instruments and Applications along with ideas for building one of these normally expensive devices for next to nothing.

What's New as of V6.40

• There are now two sets of high quality fully regulated low voltage DC inverter driven HeNe laser power supply designs including PCB layouts that can be replicated and easily modified for various size lasers. See "Sam's Modular HeNe Laser Power Supply 1" and "Sam's Modular HeNe Laser Power Supply 2" in the chapter: Complete HeNe Laser Power Supply Schematics.

What's New as of V6.25

• There is much more information on vacuum systems and technology and as a result, this material has been given a chapter of its own: Vacuum Technology for Home-Built Gas Lasers. Additions include specific details on many Hastings thermocouple vacuum gauges and their testing, repair, and sensor cleaning; capacitance manometers, powering up a turbo pump, and more.

• Wiring information for the Cyonics/Uniphase 22XX and Spectra-Physics 16X lasers has been expanded in the chapter: Complete Ar/Kr Ion Laser Power Supply Schematics.

What's New as of V6.10

• The chapter: Home-Built Diode Pumped Solid State (DPSS) Laser has been greatly expanded with additional diagrams, construction details, and parts suppliers.

• The Laser Equipment Gallery now has a large collection of photos on the Coherent Compass 315M and 532 green DPSS lasers. There is also detailed information on the internal wiring and drive requirements for the C315M laser in the chapter: Solid State Lasers.

• New information on vacuum systems for home-built lasers has been added to the chapter: Amateur Laser Construction. This includes more on rotary vane vacuum pumps and their maintenance, home-built thermocouple vacuum gauges, vacuum testing without a vacuum gauge, and sources for vacuum equipment and supplies.

What's New as of V5.90

• There are now chapters on the Home-Built Pulsed Solid State (PSS) Laser (small but growing) and the Home-Built Diode Pumped Solid State (DPSS) Laser (which is quite well along).

• A link to the Center for Microwave and Lightwave Engineering (located in the Electrical and Computer Engineering Department of Drexel University, Philadelphia, PA) has been added to the Table of Contents. CMLE is where I am actually doing some real laser work. :)

What's New as of V5.60

• Sam's Laser FAQ now has its own Web domains: laserfaq.com, laserfaq.net, and laserfaq.org. Going to one of these will redirect you to a Web site with a recent version of Sam's Laser FAQ. A German translation is also under development and will be available there and at laserfaq.de in the future.

• The chapters on solid state lasers have progressed significantly and there is now a separate one on Complete SS Laser Power Supply Schematics with complete systems suitable for driving the pulsed ruby and YAG laser heads common on the surplus market.

• A couple of really ancient versions of Sam's Laser FAQ and a link to another one have been collected at the Sam's Laser FAQ Archive just to offer an idea of how this collection evolved. If nothing else, it beats counting sheep for insomnia. :)

• Copyright notices have been added to the start and end of all text files. I did this after finding bits and pieces of Sam's Laser FAQ at random Web sites around the World with no mention of origin or author and dead links to pages that might have had these attributions.

What's New as of V5.35

• The chapters on Solid State Lasers and SS Laser Power Supplies have become more complete and this effort is still progressing. There is also the start of a chapter on SS Laser Testing, Adjustment, Repair.

• There is now a chapter on Laser Experiments and Projects. This is mostly just a list of suggested topics and links to a few laser project Web sites at the moment but should be filled in as time passes.

• This welcome page has gotten a little structure. :)

What's New as of V5.20

• The chapters on Solid State Lasers and SS Laser Power Supplies have finally arrived (though they are somewhat sparsely filled in at present). Stay tuned. :)

• There are several sections in the chapters on Helium-Neon Lasers and Home-Built Helium-Neon Laser describing the use of HeNe laser tubes with one or two Brewster windows for the construction of external mirror HeNe lasers using readily available components.

• Schematics have been added for several new HeNe laser power supplies as well as a couple of argon ion laser heads (including the very common Cyonics/Uniphase 2214).

• The information on Helium-Cadmium Lasers has been consolidated into a chapter of its own.

• One of the new wings of the Laser Equipment Gallery presents the dissection of a green laser pointer based on diode pumped solid state frequency doubled technology. Don't miss out on all the exciting (and gory) details! :)

What's New as of V5.00

• A new chapter on the Home-Built Pulsed Multiple Gas (PMG) Laser which is relatively easy to construct and may use argon, krypton, xenon, oxygen - maybe even plain ordinary air.

• Several new schematics including one of the Spectra-Physics 261A exciter which is used to power the SP-125 large frame helium-neon laser.

• A Portal to The Laser, Optics, and Holography Ring. This is an inter-navigable Webring of related sites.

• The paper: Micro-Laser Range Finder Development: Using the Monolithic Approach presents a system using a Nd:YAG laser and OPO which is pumped by the electronic flash unit from a single-use (disposable) pocket camera.

• Many new wings as well as expansion to existing wings in the Laser Equipment Gallery.

• A Link page to the CORD Lasers/Electro-Optics Series of On-Line Courses. (No longer valid.)

  (Note: As of Summer, 2002, these courses have been removed from the CORD Web site supposedly due to the expiration of their funding. While the courses are available for purchase in print form, It's a pity that this has happened. Print is not the same as on-line, even if it were free. I am looking into hosting them on one of my Web sites but suspect that in the end, such a request will be denied due to commercial interests winning out over availability of information.)

What's New as of V4.75

• The Comprehensive Table of Contents now provides Direct links to every chapter and section from one Web page.

• Several more ion laser schematics have been added including a couple of basic power supply designs that are easy to build as well as the circuit diagram of the quite common NEC GLG-3030 laser head.

• Several chapters including the one on home-built lasers (that was quite bloated) have been split to decrease loading times.

• Several new wings have been added to the Laser Equipment Gallery including one with photos of a Coherent 541 flowing gas CO2 laser - essentially a commercial version of the type of system that can be built by a determined amateur.

What's New as of V4.40

• The Laser Equipment Gallery has been expanded to include photos of a large CW YAG laser, "BUGBLASTER SR", a larger HeNe laser, and some other miscellaneous laser bits. :-)

• The general organization of some material has been improved and Sub ToCs now provide links to all sections, not just major topic headings.

What's New as of V4.25

• Diagrams for all seven types of Home-Built Lasers similar to those found in the Scientific American articles are now included in the chapters on amateur laser construction. The drawings show the basic structure and power supply for each laser assembly and should provide at least some of the overall flavor of what is involved in building these devices from scratch.

• The Laser Equipment Gallery provides a variety of Photos of Lasers and Laser Related Equipment inside and out. New wings will be added as material arrives.

  Note that this extensive set of photos is in addition to all those found in Sam's Laser FAQ. Due to the number of bits in these graphics files, the current FAQ distributions only include a page that provides links to sites where they are resident.

What's New as of V4.00

• Argon and Krypton Ion Lasers are now covered in great detail providing the only known readily accessible detailed discussion of their characteristics and maintenance, as well as power supply requirements and system design considerations for these very desirable devices. There are even complete schematics for several different Ar/Kr ion laser power supplies!

• Two complete chapters provide extensive information on Amateur Laser Construction including material from the Scientific American collection "Light and its Uses" as well as the email, Web sites, articles, and experiences of those who have been successful in building their own lasers from scratch (not taking the easy way out and using commercial tubes or laser diodes!) and getting them to work - or have given it their best shot trying! Also included: basics of vacuum systems and glass working, where to get strange parts, the well equipped home laser lab, and much much more.

• A chapter on Carbon Dioxide Lasers is included as well.

• The text formatting has also been greatly improved including a complete Sub-Table of Contents for each chapter and intra-FAQ hot links that now work!