The Chartreuse Coruscation

[CDBEAM777]

Been thinking.....what I am really worried that might happen....IF I combines ….mmmm….say 1200 mW /520NM Green from the NDG7475.....mixed in with the output of the GH0631IA2GC Red LD @ 300mW.....well....I could end up with a color of ….say......perceived at 532NM....WOW....THAT IS A BIG BUST !!! If I want a watt of 532NM..Just get a Jet Pro @ 800 $$ !!!!!!! 532NM is a nice color....but....not unique !!!...Old News !!

Just thought I would state the possible/obvious....B4 anyone else points out this " Could Be"outcome !!!

SOooooo…..The conclusion....either I tame these two multimode diodes….and hammer the geometry into some acceptable Far Field profile....or Shit Can the Chartreuse concept....and go with a NDG7475/N462 mix !!!

We shall see !!!

CDBEAM

Added Note....There is ONE possible Escape from the above Conundrum !!!! Combine an ...er...ah...say 500mW 532 DPSS module....with a GH0631IA2GC Red LD.....BOTH have tight geometry...and...THAT mix may deliver a tight beam Chartreuse !!!!……HMMMMM....May be able to fit this on the CHC H-BE format....because.....those sources will likely NOT need C-Lenses.....Hmmmm….Crap....500 mW of 532 is NOT cheap !!!!!! It is NEVER easy !!!!

 

[paul1598419]

I get the feeling, Bob, that if it were easy, you wouldn't be interested in doing it at all.

 

[CDBEAM777]

Yea....Easy is fer Wimps !!! I enjoy spending hours and hours tweaking the alignment.... to as near perfection as is possible !!!,,,,mmmmm….That sounds....er….ah....like compulsive behavior !!! Yea...OK !!!...….So What !!!

SO....Now we are faced with a possible new direction !!! Incorporating a 532 module vs. a Direct Diode. Actually.....this direction would be a real shift in basic concept....from attempting to optically tame the Multimode beasts.....to starting with a well behaved, limited divergent DPSS and a Single Mode LD...right from the start!!

Sounds good to me !!!

See the attached drawing. The concept is shown using the Jetlaser 532 OEM 500 mW @532nm Module with collimation. Note we have eliminated the C-Lens set !! I predict it will not be needed !!!

SO...maybe we can eliminate the Beam Expander also ????? !!!!! Dunno ????

I know I am jumping around.....but...In a project like this.....one must remain....flexible !!! Many, many roads....many lead to a dead end.....I continue to try to think..."On Multiple Levels...in Multiple Dimensions..." Hahahahaha !!!

I cannot remember...has a DPSS module been combined with a Single Mode LD in any past project ????

In closing....Yes...this approach will not have the output power of the 2 x Multimode LD / CLens/Beam Expander......but then...it may possibly have a much improved beam.... more gaussian ….approaching circular....limited artifacts.....ALL at the Chartreuse Color !!!

 

[RedCowboy]

I'm sure that dpss 532nm and direct 650nm have been combined to present as yellow, likely a pretty good match.

 

[paul1598419]

I have one that does this and the 532nm is less divergent than any single mode red diode. So, in the far field the red is a lager spot than green. It may be your best bet is two single mode diodes as that might match up better. But, then you give up a lot of power.

 

[CDBEAM777]

Well....The real goal would be to purchase a Red and Green source with VERY close divergence !!!...AND very tight divergence....IF I am going down that road !!!..
Hmmm...we have three (3) forks in the road !!

1) Optically adjust for the best possible Far Field beam geometries with the existing NDG7475 / HL63193 combo
2) Switch to a Jetlaser OEM 532 / H0631IA2GC Red LD combo
3) Dump the Red/Green Chartreuse dream....and convert to a Cyan Cannon II ( Blue / Green )

Paul, What 532 module do you have ? Is it the Jetlaser 532 OEM ?? It would be more than annoying to buy the Jetlaser OEM 532 / H0631IA2GC Red LD combo.....to find out....I get a Too wide RED !!!....Crap...I already have that situation with the current High Power combo.....AND...I get the color I am after !!!

Nothing is easy...but then.....LPF members would be bored with easy....well....all relative....I am sure....they are amazed with this project !!

RB...Yes...I know the DPSS/Single Mode has been done....BUT...in a Hand Held. ???...I cannot remember one !! But then....I have a challenged memory core !!

Thanx for your help !!!

CDBEAM

 

[logsquared]

Bob you should try the sharp 700mw before you give up. They are only good for 750mw max room temp so you might need 2 pbs'd to get the color match with green diode.

 

[paul1598419]

@ Bob

I haven't tried the Jetlaser 532nm. Mine is an RGB combination using the 532nm with two single mode diodes. One 650nm and the other 450nm. The green is very tight, so the blue and red are larger spots in the far field.

 

[CDBEAM777]

Thanx for the update Paul !!

Chris...I see on PL we have talked about the Sharp 700mW 638 Diodes (GH0637AA2G) before....back about a year ago.

I assume this is a Multimode....BUT....with a less divergence the Oclaro 63193 I am using now,....BUT....on PL....the knee was determined to be 716 mw....so....maybe slightly less output than the Oclaro 63193....but.....LESS DIVERGENCE !!!

SOOoooo any diodes....SOooo little $$ ….I WANT IT ALL !!!

Still....for 26 bucks for the Sharp 700mW 638 Diodes (GH0637AA2G)...…?????? I dunno ????? As I have noted in the past....I have always thought the Oclaro 63193 remained the best compromise in a Multimode @ 638nm....Output vs. divergence vs wing artifacts !!!

I have more things to fiddle with !!!

Just to try something else...a few days ago...I switched to the G2 Colli.....away from the 2mm EFL...….maybe I will switch back !!!! Theoretically…..the 2mm EFL Colli SHOULD deliver less divergence on the Oclaro 63193 !!!

As one currently views the Far Field.....at 15 Meters.....the Red Oclaro....does extend ever so slightly past the Green profile !!! Drives me nuts !!
( Yea...I know....Short Trip )

Well....for now....I will switch back to the 2mm EFL Colli….and see what it looks like ???? Maybe before......I did not have the separation distance set optimally on the C-Lenses ??????

Stay tuned....More Optical Magic to be seen.....Perhaps....I will just order a Sharp 638 Diodes (GH0637AA2G) from Jordan !!

CDBEAM

 

[CDBEAM777]

Well...we continue the saga ! I changed out the Colli...back to the 2mmEFL. To my surprise....The G2 does a much better job at correcting the astigmatic divergence....SO...I will stick with that !!

Anyone know the focal length on the G2 Collimation Lens ?

I have been adjusting the separation distance between the C-Lenses...over, and over, and over....and I have finally achieved a equal Far Field geometry....SO.....Now....I transfer all the components....to the actual H-BE platform......and start ALL over. The Test Bed Ally plate serves as a template for the final bore/tap pattern on the H-BE....SO....at least that is a head start.

For now....I will stick with this Diode combination. One configuration I just thought about.....the Jetlaser OEM 500mW @ the 532 line....combined with the either the HL63193 or the Sharp 700mW 638 Diodes (GH0637AA2G) ….HMMMMM ?????

I sent Jetlaser a message on Thursday asking some questions about their OEM 500mW / 532 module....specifically...can it's output be modulated ??
They said...." We will answer your question ASAP "....no further reply.


CDBEAM

 

[RedCowboy]

Rear FL is 2.39mm IINM

 

[paul1598419]

That is my understanding too. The back FL is 2.39 mm. There are other examples of this lens that differ slightly in EFL, but I don't think it will make a huge difference here.

 

[logsquared]

The "BFL" doesn't really help figure out the power of the lens. Its the EFL that's important for what we do. The G2 is 4mm EFL.

 

[RedCowboy]

The lens is 3.3mm thick and the rear FL is 2.39 so to the lens center would be 1.65 from the rear 1.65 + 2.39 = 4.04mm EFL

I have seen them listed as 4.02

 

[CDBEAM777]

HMMM....Thanx for the EFL info .....I can tell you....for a fact that the G2 does a better job at initial collimation than the 2mm EFL....and...delivers a improved beam Far Field when then running thru a set of 6X Cylindrical Lens. This real life outcome surprises me....but...I am happy with the result !!
There always seem to be new discoveries....and new things to be learned..... even with our extremely limited resources !! Thanx for your info !

CDBEAM

 

[logsquared]

HMMM....Thanx for the EFL info .....I can tell you....for a fact that the G2 does a better job at initial collimation than the 2mm EFL....and...delivers a improved beam Far Field when then running thru a set of 6X Cylindrical Lens. This real life outcome surprises me....but...I am happy with the result !!
There always seem to be new discoveries....and new things to be learned..... even with our extremely limited resources !! Thanx for your info !

CDBEAM

The G2 is a great lens. Whatever aspheric constants they used to get the profile seem to work for any diode thrown at them. The 2mm EFL's by nature are gonna have 2x the initial divergence. So will need 4x the correction to get the same power density in the far field. The real pain with the 2mm is getting the centering of the diode perfect as well as the focus being so dang touchy. One thing I have found is the distance from the 2mm to the first lens of the beam expander greatly affects the magnification. A few millimeters dramatically change the far field spot.