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I have been working on several laser related projects lately and this is one of them. Here are a few pics of my 445nm optical experiments. I decided to trial Anamorphic prisms riding on the front end of a Jayrob 532 DIY with a microboost driver set to max, a copper heat sink and the 445 lens from LarryDFW. I had a set of these prisms I was experimenting with in 2000. They are from Frontier Optics. I do not know if they are BK7 or SF11 material. They are not coated for 445nm.
Transmission losses are as expected…around 20%. With no prisms: 1110 mW …with prisms: 868mW. Beam is corrected somewhat. At 10’ with no prisms: 5.5mm x 1.25mm. With prisms: 4mm x 1.25mm.
The small set of Anamorphic prisms are positioned within 2 pcs acrylic flat stock at 31.2mm square...same size upper and lower...three flat head bolts are used to clamp the prisms in position. The result is an " Anamorphic Sandwich Assembly "...or ASA.
I was very lucky because the prisms are 11.77mm tall….which is just the same diameter of the Larry DFW focus ring. The ASA fits very snug on the OD of the focus ring. The final acrylic shroud/tube was added to protect the assembly…and for effect.
I experimented with many set angles for the prism set. There is a free program you can down load (Mathematica Player 7) which runs a virtual Anamorphic Prism set-up application. Very interesting. I still am not sure I have the best position???...I do have the maximum mW output for this set of prisms. It is known that the prism material should be BK7 and coated for minimum losses. I do not know what these prisms are made from…likely SF11 glass which has more transmission loss than BK7 glass.
The main purpose of this project was to show that additional beam shaping optics can be adapted for pointer use.
In conclusion…the use of prisms does somewhat lessen the fast axis divergence of the 445LD…but at a substantial loss of mW output…at least for the set of prisms I have. I have been informed by one overseas optics company that a specific coating for 445nm will decrease the transmission losses down to approx 15% and improved transmission will occur with BK7 glass vs. SF11. The use of anamorphic prisms may be acceptable if losses could be reduced to 10% or lower. Dr Lava is currently working on a Lab style set-up for the 445LD which will use TEC for thermal management and Cylindrical lenses to beam shape the output. No details are currently available but his optics choice MAY deliver less loss( less than 5% ).
CDBEAM
Transmission losses are as expected…around 20%. With no prisms: 1110 mW …with prisms: 868mW. Beam is corrected somewhat. At 10’ with no prisms: 5.5mm x 1.25mm. With prisms: 4mm x 1.25mm.
The small set of Anamorphic prisms are positioned within 2 pcs acrylic flat stock at 31.2mm square...same size upper and lower...three flat head bolts are used to clamp the prisms in position. The result is an " Anamorphic Sandwich Assembly "...or ASA.
I was very lucky because the prisms are 11.77mm tall….which is just the same diameter of the Larry DFW focus ring. The ASA fits very snug on the OD of the focus ring. The final acrylic shroud/tube was added to protect the assembly…and for effect.
I experimented with many set angles for the prism set. There is a free program you can down load (Mathematica Player 7) which runs a virtual Anamorphic Prism set-up application. Very interesting. I still am not sure I have the best position???...I do have the maximum mW output for this set of prisms. It is known that the prism material should be BK7 and coated for minimum losses. I do not know what these prisms are made from…likely SF11 glass which has more transmission loss than BK7 glass.
The main purpose of this project was to show that additional beam shaping optics can be adapted for pointer use.
In conclusion…the use of prisms does somewhat lessen the fast axis divergence of the 445LD…but at a substantial loss of mW output…at least for the set of prisms I have. I have been informed by one overseas optics company that a specific coating for 445nm will decrease the transmission losses down to approx 15% and improved transmission will occur with BK7 glass vs. SF11. The use of anamorphic prisms may be acceptable if losses could be reduced to 10% or lower. Dr Lava is currently working on a Lab style set-up for the 445LD which will use TEC for thermal management and Cylindrical lenses to beam shape the output. No details are currently available but his optics choice MAY deliver less loss( less than 5% ).
CDBEAM
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