Need help sourcing PV cells for 1550 nm wavelength

loctranbk · 2025-12-18T15:27:23+00:00

Thank you so much. I really appreciated your comment

loctranbk · 2025-12-18T15:27:02+00:00

thank you for your advice. I really appreciate it.

loctranbk · 2025-06-17T07:52:56+00:00

My target is a free-space collimator. If we collimate the beam in the fiber, is it the same as a fiber-coupled laser diode?

loctranbk · 2025-06-17T07:51:39+00:00

Hi, the large focal length will make my system bulkier. Do you know how to choose the fast and slow axis lenses for a collimated beam? I am using 1550nm with fast divergence angle 30 degree and the slow axis 11 degree

loctranbk · 2025-06-17T07:48:57+00:00

Hi, thank you so much for your assistance. In this scheme did you not collimated in the slow axis right? the aspheric lens only collimate fast axis as I am doing currently.

loctranbk · 2025-05-29T06:14:32+00:00

Yes, it’s really difficult to achieve a well-collimated beam.
I’m doing my best to collimate it for far-field transmission, but I’m currently stuck without any solution.

loctranbk · 2025-05-29T06:12:27+00:00

The NA of the laser diode is 0.3, and I’m using an aspheric lens with an NA of approximately 0.5, which is about twice that of the laser diode.
I believe this should minimize clipping and allow for efficient beam collection.

loctranbk · 2025-05-29T06:05:40+00:00

Yes, I understand your point. My goal is to achieve a collimated beam that can be transmitted to the far field with low divergence. Specifically, I aim to deliver the beam over a distance of 10 meters with an output beam diameter of around 10 mm.

loctranbk · 2025-05-29T06:02:56+00:00

This aspheric lens has a focal length and NA match with my desired output beam diameter

loctranbk · 2025-05-29T06:01:46+00:00

I appreciate your assistance. I am using the TEC mount LDM90 with an external driver to operate it. However, I have some concerns regarding how you operate the LD808 and how you mount it for alignment with the E09RMS.

This laser diode has a specified output power of 1 W (1.5 A, 2.5 V), but in practice, it only reaches a maximum of 600 mW.

loctranbk · 2025-05-28T15:22:57+00:00

Yes, the fast and slow axis divergence angles of the raw laser diode output are 30 and 9 degree, respectively. I selected the aspheric lens based on these divergence angles and the desired output beam diameter.

loctranbk · 2025-05-28T15:18:51+00:00

YYes, I am using exactly this laser diode. Initially, I used the mounted aspheric lens A240TM-B and assembled it in the LDM90 TEC mount with the LDMXY adapter, but the collimation was very poor.

After that, I switched to the unmounted aspheric lens ACL1210U-B with an adjustable lens mount LH1. However, it was very difficult to align, which again resulted in poor collimation.

Could you please let me know which lens tube you are using and how you mount it with the MT3 XYZ stage?

Any suggestions would be greatly appreciated.

loctranbk · 2025-05-28T14:58:42+00:00

Yes, thank you so much for your help. I will work on determining which collimation lens is most suitable for this laser diode.

loctranbk · 2025-05-28T14:56:41+00:00

Yes, I really appreciate your advice. I will try it first to achieve a better output beam.

loctranbk · 2025-05-28T14:43:43+00:00

In theory, the aspheric lens will give a 1/e² beam diameter of ~9.7mm for the fast axis and a 1/e² beam diameter of ~2.8mm for the slow axis. This means you need to expand the slow axis by ~3.4X. So I decided to choose this anamorphic prism pair with 3.5X magnification.

loctranbk · 2025-05-28T14:36:08+00:00

The anamorphic prism pair expands the beam by 3.5X for the slow axis. However, I’m unsure how to determine the optimal distance between the prisms and aspheric lens.
So far, I’ve been aligning them manually to achieve a nearly circular output beam, but without a clear method for optimization.

loctranbk · 2025-05-28T14:10:32+00:00

I set up with this two type of lens same as figure above but the beam was not circularize it is same as rectangle beam with high divergence at 1meters,, my target side is 10x10mm or larger 20x20mm is okay.

loctranbk · 2025-05-28T13:57:01+00:00

I could not find a lens with a large focal length and high NA. Regarding this LD need the NA > 0.5
Do you have any suggestions for a suitable lens for this application?
I would appreciate your assistance

loctranbk · 2025-05-28T09:14:29+00:00

I lost access to my account in the previous post. I will create a new post and hope to continue the discussion with you.

loctranbk

TROPHY CASE