This Part 2 Continues presently as a follow on of the historic topic of the optical pumping effect we have examined in Part 1. - The original historical discovery of the effect at CNRS in Paris, long before the lasers.

 

We shall examine presently however, the potential of the Ruby R Line once accessed by the optical pumping: And at a time however now, no longer that far long preceding the lasers-as in Part 1. And briefly, a new effect of special significance shall manifest itself, that of which little is known, hence told here in what follows presently

 

On Crystalline Ruby

 

The Crystalline Ruby is made up of a Sapphire crystal, doped with Chromium however, and that in which Chromium enters the crystal doubly ionized. And heavier doping the crystal, the Ruby, takes on a darker color.

 

And yet further:

 

It had been known for sometimes now, and of special significance for us here:

 

That the Chromium ions in the crystal develop 2 closely spaced high-lying energy states: High-lying however, in the red region of spectrum at above the crystal's ground electronic energy State.

And Thus: Defining the two closely spaced Ruby R Lines.

And, closely spaced, by a value lying in the then 'as yet unknown value in the RF region of spectrum'.

And, at the time yet, this entire discovery, the 2 closely space R Lines in Crystalline Ruby, the doping and the crystal growing and all else covered here presently, In its entirety: Had Been developed, and in its entirety, at the 'Bell Telephone Laboratories' in Murray Hill New Jersey' - A matter to keep in mind.

 

And now:

 

Again the credit goes to Alfred Kastler at CNRS in Paris, And at a time he had been considering for sometime: To investigate the potential of Ruby R Lines once accessed by his Pompage Optic, the optical pumping. Yet knowing full well however, that this entire technology needed solely existed at the Bell Telephone Laboratories in Murray Hill.

 

The 'Story' now further continues. The time and the date of the events due to occur, as it proved, now approached the June-July time frame the year 1960:

 

At the time Alfred Kastler at CNRS had already approached the Bell Laboratories. And had arranged for his senior member of his staffs at CNRS -- Jean Brossel -- to move to and spend a full year at Bell Laboratories. As much had been anticipated of potential of Ruby R Line accessed by optical pumping.

 

	Alfred Kastler (1902-1994)		Jean Brossel (1918-2003)

 

Things had moved fast. And as it proved, within month time of this same time frame: the timing would approach the event that initiated the very beginning of the laser, the historic 12 December 1960 event.

 

The Story now yet continues at the Bell Laboratories, in June-July time frame the Year 1960

 

And Briefly: Right across from my laboratory at Bell and a bit down the Hall. The experiment had been ongoing in a laboratory, investigating no longer a potential:

 

But However: Inducing by the pumping effect, the Ruby R Line into it's now Inverted energy State. Anticipating that it can be possible to drive it in its inverted energy state, into its self-sustained oscillation mode, and thus operating it as a Laser for the first time, in the red region of the spectrum. What had been designed and anticipated by Jean Brossel at the Bell laboratories.

 

Yet, weeks and time had passed: Anticipating by the optical pumping to induce the crystalline Ruby into its now inverted energy state. And yet and yet as it proved, the 'Efficiency', in inducing the Ruby R Line into its inverted energy state: Turned out to be as it seemed, to be 'negligibly small'. And in no way did it seem possible, to invert the Ruby R Line at a sufficient number-density by the pumping effect needed drive it into its self-sustained oscillation mode in the red region of the spectrum as had been anticipated and planned for.

 

Yet now, in Lasers:

 

In Lasers, the history of events is always an exciting story, and often taking place itself within an already ongoing exciting story in itself.

 

And unknown to any one of us at the Bell laboratories. There had been ongoing an exciting experiment on the Ruby R Line, at the "Hughes Aircraft Company in Malibu, outside of Los Angeles in southern California".

 

Here is the Story:

 

I think it was early in July, I had a telephone call from Willis Lamb at Stanford University in Palo Alto (I knew Willis closely, as I shall explain). Telling me that Ted Maiman at Hughes Aircraft Company in Malibu: Had just then driven the Ruby R Line, into its Oscillation Mode in the red region of spectrum.

 

And that however, and as he had learned, the Oscillation "Self-terminated itself", emanating an intense short duration laser pulse of a fraction of a millisecond pulse duration.

 

And that as the news had it and we learned shortly thereafter: He had used a specially designed flash lamp emitting an intense short duration light pulse at a very high intensity for his optical pumping effect. Far different from what was being used at the time for optical pumping at Bell Laboratories. An exciting story told here shortly below.

 

And on Ted Maiman: He had performed his Doctoral thesis research at Stanford University, with Willis overseeing his thesis research. And that further, he had joined Hughes in Malibu, and within a number of months time following his graduation. And then this Above

 

It is remarkable that, Ted Maiman did all of this above in just a few moths time since he joined Hughes in Malibu, CA. And with little funds available to him at Hughes, as we now know.

 

Here is now this exciting Story, told here for the first Time

 

And, there shall be a concluding Note - Which shall conclude this Part 2

 

We do not know how and in which way he chose a flash lamp of a short duration for his optical pumping. Which has special spectral properties of a very short duration, which extends over an exceptionally broad bandwidth into the deep 'Ultraviolet in near UV'. And far different from the then available light sources in the red region of spectrum being used for the pumping effect ongoing at the Bell laboratory at the time.

 

And as for his design as he had developed it was made up of his well known, helical flash lamp with a crystalline Ruby held along its helical axis of about ten cm long.

And, in what followed in his design proved a strictly an electrical engineering undertaking of which not much is known.

Charging a fairly large Capacitor Bank, to what as we know, at up as high as '3000 Volts', And 'discharging it' in a fraction of a millisecond time in his helical flash lamp design .

And, thus the resulting intense flash lamp emitted light of a short duration, and with its special spectral properties extending into the deep UV:

Would now excite the Ruby R line present in its 'ground' energy state: Into its high-lying energy state at near its ionization potential lying in the UV:

The effect thus 'depletes' the entire stored energy present in the ground electronic Energy state of the Ruby R Line, thus exciting it, and interestingly, into high-lying energy states 'as high as in the near UV'.

And then by cascade: It shall 'decay' into the Ruby R Line excited energy state in the red region of spectrum at above, its now fully depleted ground electronic energy state.

Thus inducing, the Ruby R Line into its now fully 'Inverted' energy State in its red region of spectrum. And, thus hence, the crystalline Ruby shall break into, what proved to be, its 'Self-terminating' oscillation mode, however:

Emanating at its output a pulsed intense laser light beam in the red region of spectrum, and for the first time - in late June or early in July the year 1960.

 

We shall however keep in mind, the necessity for charging and discharging the capacitor bank, which takes a period of time in tens of minutes, and limiting its potential use to where a single, high intensity laser light pulse of a short duration shall suffice.

 

A Concluding Note, and Briefly:

 

 

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