×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

ZEMAX: Diode Stack Fast Axis Collimation for coupling

ZEMAX: Diode Stack Fast Axis Collimation for coupling

ZEMAX: Diode Stack Fast Axis Collimation for coupling

(OP)
Hello!

So I've been working on a project to couple a 15 bar diode stack into a 600 micron fiber. Using an old design that I've used in the past but it's giving me some issues. I don't have a plethora of experience with ZEMAX so I'm hoping to leverage the collective consciousness of the internet for some assistance.

I tried using a hybrid simulation first to minimize the spot size and then translate it to a pure nonsequential setup but that didnt' work quite so well. And I'm having little to no luck using the MFE to optimize the Non Sequential layout.

The basic setup is a diode stack, a bi-convex cylinder lens, a plano-convex cylindrical lens, a plano-concave cylindrical lens, and an aspheric lens. All I've been able to do is get the spot size to approximately 0.7 mm but I'm told that it's possible to get it smaller as it's been done before.

The Diode Stack I have configured as follows:
# of Layout Rays: 100
# Analysis Rays: 1000000
Power (Watts): 1500
Wavenumber: 0
Color #: 0
Astigamatism: 0
X-Divergence: 1.146
X-SuperGauss: 1.000
Y-Divergence: 0.229
Y-SuperGauss: 1.000
Number X': 5
Number Y': 15
Delta X: 0.5
Delta Y: 2.0
X-Width: 0.400
X-Width Hx: 5.000
Y-Width: 1.000
Y-Sigma: 1.000
Y-Width Hy: 1.000

This is for a pretty standard diode stack that you can get from most suppliers, in this case Jenoptik. They do both Fast and Slow Axis Collimation on the stacks so I tried to shortcut that by approximating the size of the beam post-collimation lenses. It ends up being a rectangle (per emitter) of 0.5 mm by 1 mm by the time its' exiting the lens. That was the assumed expansion anyways. There are more than 5 emitters per bar but just using a simplification. This may be where a majority of the problem lies.

Following this diode stack is the bi-convex cylinder lens. The two radii are 109.4 mm and the dimensions are 40 by 20mm made of N-BK7.

Object Type: Toroidal
Z Position: 70.6 mm
Material: N-BK7
Radial Height: 20.000
X Half-Width: 10.000
Thickness: 5.000
rotation R1: 0.000
Radius1: 109.400
Radius 2: -109.400

Followed by a Optosigma lens: 022-0662. I rotated it by 180 degrees about the Y -axis and 90 Degrees about the Z-Axis. It's Z-Position is 43.6mm from the Bi-Convex Lens.

After that, another Optosigma Lens: 022-1255. located 22.4 mm from the previous lens

The main point of this entire simulation was to find approximately where to place 1 of 2 aspheres. 1 is a custom lens:
Object Type: Even Asphere
Tilt About Y: 180
Material: SF10
Radial Aperture: 12.368
Thickness: 5.000
Radius 1: 12.368
Conic 1: -1.107
a2 = -0.021477756
a4 = 1.0005501e-005
a6 = -5.7028691e-009
a8 = 7.0445577e-011
a10 = 5.3181675e-013
a12 = -3.3489312e-014
a14 = 3.39617225e-016
a16 = 1.5218404e-018
Radius 2: 0
Conic 2: 0

The best I've been able to accomplish in the fast axis is 0.7 mm spot size. I need to do better. Slow Axis I'm less concerned about for the time being. Anyone have any ideas what I might be doing wrong? Or a way to use the optimizations tools in NSCE?

I can provide some more details or some pdfs of Zemax things I've done. Just let me know

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources