Couple External Light Source (laser) into Light Commander

Hello all,

I would like to know what steps one must follow to couple in an external light source into the DLP light commander.

Thanks.

Peter

  • Hello Peter,

    Welcome to the E2E community and thank you for your question regarding the Light Commander kit. 

    Before discussing the necessary steps to couple in an external source, it would be useful to know more about how you are planning to couple the laser optically into the DMD (this will determine the changes that must be made to the optical core module).  It would also be helpful to know how you would like to control the new illumination source (for example, triggered externally or by the Light Commander). 

    Once we know a little more detail about your intended setup it will be easier to outline the necessary steps.

    Regards,

    Raul

  • In reply to raul55377:

    Hello Raul,

    Thank you for the quick reply. My overall plan is to have a high power 532 nm green laser with Gaussian mode shape shine on the DMD and imprint an image.

    As for coupling it into the DMD, I just plan on having my laser beam go through some beam shaping optics to make the spot size (fundamental Gaussian) the DMD. I assume I can have it take the same light path as the LEDs if I move them out of the way. I have two plans: one is to use a small laser pen, the other is to use a large external laser. For the small laser pen, perhaps it is possible to fit it in the box where the LEDs currently are (I have not yet looked at how much free space is inside the box yet). For the large external laser, it cannot fit inside, so I must couple the light in from the outside somehow. Since the DMD is not designed to reflect light from the input aperture, I must make a new aperture somewhere on the side (i.e. remove all internal components then get our Machine Shop to cut a hole), then insert some guiding optics (e.g. mirrors) inside the DLP LC to guide the laser beam to the DMD. If the DMD could be designed to reflect light from the outside, then I could just use the current aperture and avoid damaging the box/components.

    Both laser sources will be controlled independently from the DLP LightCommander, so that is not an issue.

    I eagerly await your answer.

    Thanks,

    Peter

  • In reply to Peter DeVore:

    Peter,

    Thank you for the clarifications. 

    The Light Commander kit has an illumination module (LED module) and a core optics module that includes an integrator rod to improve illumination uniformity over the DMD.  I would recommend removing the LED module and having the laser beam go through the integrator rod so that the light path remains the same.  To make use of the integrator you need to use a lens that expands the cone angle of the laser at the input end;  I asked our optics engineer what that cone angle should be and will send you the information as soon as I have it.  The other option would be to bypass the integrator and use different beam shaping optics.  In this case you would need to know the curvature and distance of the mirrors used in the core module in order to select the right spot size for the laser beam.  For this I would recommend contacting Logic PD to get the mechanical specifications.    

    I will post a follow-up message with the missing information; in the mean time I hope this helps you.

    Regards,

    Raul

  • In reply to raul55377:

    Input beam to the integrator rod should be F/1.0 - 30 degrees (1/2 angle).

     

    Please let me know if your question is still not answered or if you have any other ones.

    Regards,

    Raul

  • In reply to raul55377:

    Hello Raul,

    Thank you for the reply. You have answered part of my question, that is, that the LightCommander is modular enough to allow one to change the light source. However, a few issues remain. First, I would like to use a laser, so using an integrating rod is out of the question; I would use beam shaping optics per your previous reply. Next, is it possible to bring illumination from outside the DLP LightCommander inside? I only see one aperture and am unsure of how to approach this. I will also contact Logic PD as per your suggestion, but in case they cannot come up with a reasonable answer, I will ask you as well. I also assume that Logic PD would know whether this kind of alteration affects the warranty.

    Thank you for your time.

    Peter

  • In reply to Peter DeVore:

    Peter,

    The Light Commander was designed to facilitate easy deployment on an optical bench, which should be very helpful for your application.  If you remove the top and side covers of the kit you will see that all the modules are mounted onto a metal plate.  You can easily remove the modules from the plate and place them in your optical table since the mounting holes were designed for that purpose.  Once you have the modules mounted on the bench you can take out the LED illumination module and use your own laser and beam shaping optics.  Please do follow-up with Logic to get the mechanical specs; they will also be able to answer any warranty related questions.

    Regards,

    Raul 

  • In reply to raul55377:

    Peter,

    In the following link you will find a video that explains how to remove the different modules and mount to an optical bench:

    http://e2e.ti.com/videos/m/dlp_mems/240437.aspx

    Hope this helps.

    Regards,

    Raul

  • In reply to raul55377:

    Dear Peter,

    You could also modify the DPSS light source with added optics to change the beam characteristics of your source without creating much of effect on depth of coherency.

    By doing so all you would need to do is take off the GREEN LED and shine and mechanically fix the new GREEN module without changing anything in the Light Commander optical path.

    We as a DLP design house can assist you in providing such a solution.

    Should you have any questions please feel free to contact us

    Yuval

    Yuval Kapellner
    Founder and CTO
    EKB Technologies Ltd
    www.ekb.co.il