presentation1 · wayne mefferd, bob rorden, john cullen and steve jarrett. gerry barker. our first...

May, 1966

Coherent Radiation Laboratories The First Two Years

The Beginning

• Two guys from S-P wanted to start their own company- Gene Watson and Jim Hobart

• Dupont ( the chemical company ) wanted to be in the instrument business

• Coherent had nothing proprietary so Dupont started with a $15k/mo “research “ contract

• Four other members of founding group hired-Wayne Mefferd, Bob Rorden, John Cullen and Steve Jarrett

Gerry Barker

Our First Laser

• 75 W carbon dioxide laser• Power meter for the laser• Perkin Elmer had a similar laser in the field• S-P had not entered field - tried to develop a

“ Z “ tube laser for a laser band saw• Our prototype made 15 W for a month- but

we demonstrated and delivered on time

“The Kluge”

Band Saw

Dot Farrand et al

White Light Krypton Ion Laser

• Watson and Hobart had early plans for ion laser development- had offered Bridges, Bell and Goldsborough jobs

• Holotron, a subsidiary of Dupont, contracted with CRL to build 2 “ white light “ krypton ion lasers

• Holotron had a portfolio of holography patents and money

What’s Wrong With Ion Lasers

• Very inefficient• Water cooling• 3-phase power• Destroy their own gas discharge structures• Periodic, expensive plasma tube

replacement

What’s Right With Ion Lasers

• High, Watt level power• Multiple wave lengths• High quality beam characteristics• Unique light source in 1966- He-Ne laser

limited to one visible wave length at 100 mW

How To Build Ion Lasers

• DC arc discharge• RF discharge• Insulating plasma confining structure-

quartz, BeO• Segmented plasma confining structure-

graphite, W, Mo

How To Choose

• RF• Rempel,

Goldsborough and Bell are very smart guys

• No electrodes• Simple fused quartz

tube

• DC• Much simpler, more

efficient PS• Plasma conditions and

laser power the same• Why does fused quartz

work in an RF discharge and not in DC ?

Graphite disk

Proto ion laserK

A

Management Matters

• Hobart organized a trip to Ed Labuda at Bell Labs instead making a decision in a vacuum

• Watson brought in Earl Bell one midnight to look at dc ion laser

• Watson then made contact with Leo Cronin at Spectra-Mat for cathode development

• Hobart hired Gerry Barker to join ion laser development

W dispenser cathode- in line

Mefferd Solves Problem

• How do you hold bore sections in place ?• Use difference of CTE of fused quartz and

graphite • Shrink fused quartz around each bore

section

Some Wonderful Things Happened

• Single frequency operation with high efficiency with an etalon in cavity-ideal for holography

• High power at many wave lengths revolutionized Raman spectroscopy

• Ideal for eye surgery, photocoagulation

photocoagulator

Mode locked pulse

Life Gets Interesting

• Dupont pulls out for internal reasons- we had gained “ spending momentum “

• Our management became divided- Watson leaves

• We had a financial crisis- Cullen leaves• The “ green eyed monster “ showed up in

the guise of an S-P BeO plasma tube

Refinanced

• Watson sells Coherent to Venrock before he leaves

• Three legged stool-company employees, Venrock and local investors ( Asset Management , Pitch Johnson )

• Robert Noyce joins board- co-inventor of the IC, founder of Fairchild Semiconductor and Intel

BeO disk

Cu graphite BeO

Normal Design of BeO Tube

Credit card validator-Argon laser

Nd:YAG Laser

Thanks