Path: ...!feed.opticnetworks.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail
From: Jeroen Belleman <jeroen@nospam.please>
Newsgroups: sci.electronics.design
Subject: Re: how the laser happened
Date: Tue, 25 Jun 2024 09:55:00 +0200
Organization: A noiseless patient Spider
Lines: 151
Message-ID: <v5dt05$1f7m7$1@dont-email.me>
References: <d5cb7j96v01rnj2ub44r39c9ghet2t6smv@4ax.com>
 <1ghb7jt3882078r19n6jjgtirv25q27805@4ax.com> <v55qe6$20163$1@solani.org>
 <v571as$3rs0j$2@dont-email.me> <v58ab7$21a84$1@solani.org>
 <v59j4s$e196$1@dont-email.me> <k6kg7j5rqjd4r9igl9vk329h27pos4adr8@4ax.com>
 <v59obk$f0ue$1@dont-email.me> <36tg7jl5i74ui7rvmqhbg1jl9pldjehmvb@4ax.com>
 <v5a6f5$hji2$1@dont-email.me> <oqdh7jd0junt525da0fdgnolensva9h8ls@4ax.com>
 <v5ae7e$j0sj$1@dont-email.me> <n3lj7j9ojpmg5033ueb4ogp08ni791jb4j@4ax.com>
 <f6rj7j10u7d4tspqpi3313km2hop57j595@4ax.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Injection-Date: Tue, 25 Jun 2024 09:52:38 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="fd8e8572526367a64168c906c9e49ff1";
	logging-data="1547975"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/j2MmcDIErE+diyGLJ7aUN"
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.13.0
Cancel-Lock: sha1:7BGwuwT6AtIhP4mqv0bAr2Q4BjM=
In-Reply-To: <f6rj7j10u7d4tspqpi3313km2hop57j595@4ax.com>
Content-Language: en-US
Bytes: 7607

On 6/25/24 00:02, john larkin wrote:
> On Mon, 24 Jun 2024 16:22:31 -0400, Joe Gwinn <joegwinn@comcast.net>
> wrote:
> 
>> On Mon, 24 Jun 2024 00:22:06 -0000 (UTC), Phil Hobbs
>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>
>>> john larkin <jl@650pot.com> wrote:
>>>> On Sun, 23 Jun 2024 22:09:42 -0000 (UTC), Phil Hobbs
>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>>>
>>>>> john larkin <jl@650pot.com> wrote:
>>>>>> On Sun, 23 Jun 2024 18:08:52 -0000 (UTC), Phil Hobbs
>>>>>> <pcdhSpamMeSenseless@electrooptical.net> wrote:
>>>>>>
>>>>>>> john larkin <jl@650pot.com> wrote:
>>>>>>>> On Sun, 23 Jun 2024 16:39:56 -0000 (UTC), Cursitor Doom
>>>>>>>> <cd999666@notformail.com> wrote:
>>>>>>>>
>>>>>>>>> On Sun, 23 Jun 2024 05:03:34 GMT, Jan Panteltje wrote:
>>>>>>>>>
>>>>>>>>>> On a sunny day (Sat, 22 Jun 2024 17:23:40 -0000 (UTC)) it happened
>>>>>>>>>> Cursitor Doom <cd999666@notformail.com> wrote in
>>>>>>>>>> <v571as$3rs0j$2@dont-email.me>:
>>>>>>>>>>
>>>>>>>>>>> On Sat, 22 Jun 2024 06:19:49 GMT, Jan Panteltje wrote:
>>>>>>>>>>>
>>>>>>>>>>>> On a sunny day (Fri, 21 Jun 2024 11:32:56 -0700) it happened john
>>>>>>>>>>>> larkin <jl@650pot.com> wrote in
>>>>>>>>>>>> <1ghb7jt3882078r19n6jjgtirv25q27805@4ax.com>:
>>>>>>>>>>>>
>>>>>>>>>>>>> On Fri, 21 Jun 2024 17:56:36 +0100, Cursitor Doom <cd@notformail.com>
>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>
>>>>>>>>>>>>>> On Fri, 21 Jun 2024 06:05:21 -0700, john larkin <jl@650pot.com>
>>>>>>>>>>>>>> wrote:
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> There was a thread somewhere above about photon wave/particle
>>>>>>>>>>>>>>> duality.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> This is worth reading:
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> https://www.amazon.com/How-Laser-Happened-Adventures-Scientist/dp/
>>>>>>>>>>> 0195153766
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> Einstein, in one of his fits of genius, predicted in around 1916
>>>>>>>>>>>>>>> that under the right conditions, a photon could pass by an excited
>>>>>>>>>>>>>>> atom and the atom would kick in another photon, or add to the wave
>>>>>>>>>>>>>>> amplitude, depending on how you feel about these things. He called
>>>>>>>>>>>>>>> it stimulated emission. He also declared that the laws of
>>>>>>>>>>>>>>> thermodynamics made this effect impossible to use in practical
>>>>>>>>>>>>>>> situations.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> In 1951, Charles Townes invented a work-around trick and built the
>>>>>>>>>>>>>>> maser, a gaseous microwave oscillator. His superiors thought he was
>>>>>>>>>>>>>>> crazy to dispute Einstein and almost threw him out of grad school,
>>>>>>>>>>>>>>> but it worked.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> In 1960, Theodore Maiman at HRL made the first ruby laser, and Bell
>>>>>>>>>>>>>>> Labs soonafter made a HeNe.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> What's interesting is that any decent neon sign shop could have
>>>>>>>>>>>>>>> built a HeNe laser in 1920.
>>>>>>>>>>>>>>>
>>>>>>>>>>>>>>> HRL sounds like a very cool place, up in the hills above Malibu.
>>>>>>>>>>>>>>
>>>>>>>>>>>>>> Wasn't that where Jane Mansfield used to go out bathing?
>>>>>>>>>>>>>>
>>>>>>>>>>>>>>
>>>>>>>>>>>>> Keep your mind on electronics, young man.
>>>>>>>>>>>>>
>>>>>>>>>>>>> The Getty Museum is in Malibu. Go there if you can. Hearst Castle,
>>>>>>>>>>>>> too,
>>>>>>>>>>>>> up the road a bit.
>>>>>>>>>>>>
>>>>>>>>>>>> I've been to Malibu, even did some work there...
>>>>>>>>>>>> Did not go to any museum, but did go to the beach.
>>>>>>>>>>>
>>>>>>>>>>> Did you see Jane? What about lobsters? Any lobsters around?
>>>>>>>>>>
>>>>>>>>>> Na, but some other beatiful women I met.
>>>>>>>>>> Last time we went looking for edible seaweed ...
>>>>>>>>>
>>>>>>>>> Argh! Never mind. I believe Jane had terrible problems with lobsters when
>>>>>>>>> she went out bathing in Malibu. But you don't know anything about that,
>>>>>>>>> clearly. It obviously wasn't publicised in Holland.
>>>>>>>>
>>>>>>>> This thread is about lasers, not lobsters.
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>> Well, Schawlow famously said, ?Anything will lase, if you hit it hard
>>>>>>> enough.?
>>>>>>>
>>>>>>> I expect that includes lobsters.
>>>>>>>
>>>>>>> Cheers
>>>>>>>
>>>>>>> Phil Hobbs
>>>>>>
>>>>>> But no, seriously, there must be some laser action, or at least some
>>>>>> sort of stimulated emission, some sort of super-fluorescence, in
>>>>>> nature somewhere.
>>>>>
>>>>> Sure. Cosmic masers occur in interstellar giant molecular clouds, for
>>>>> instance.
>>>>>
>>>>> The lifetime of suitable upper states drops steeply with increasing energy,
>>>>> which means that visible laser action requires much stronger pumping.
>>>>>
>>>>> While that can in principle happen naturally, it would be in places with a
>>>>> lot of other stuff going on, so it would be less noticeable.
>>>>>
>>>>> You don?t have resonators in interstellar space, so it wouldn?t be highly
>>>>> directional.
>>>>>
>>>>> Cheers
>>>>>
>>>>> Phil Hobbs
>>>>
>>>> I was thinking about a biological laser too.
>>>>
>>>> I could imagine an eyeball with some sort of stimulated emission
>>>> effect, in the vitreus humor or in the retina, to improve night
>>>> vision, basically a photon amplifier.
>>>
>>> Difficult. For a start, you need a pump source of high intensity and
>>> narrowish bandwidth, and there are no biological examples that I know of.
>>
>> Biology does make meta surfaces of various kinds, usually to make
>> reflectors impossible to make any other way, from beetles that look
>> iridescent to bird feathers.
>>
>>
>>>> Nature seems to use any effect that's not flat impossible, whether
>>>> biologists approve or not.
>>
>> True, if there is a need.  Laser eyes seem like it would attract the
>> wrong kind of attention.
>>
>>
>> Joe Gwinn
> 
> I was thinking of amplification to improve night vision.
> 

Nature chose the cheaper way: A cascade of amplifiying chemical
reactions.

Jeroen Belleman