Could you please help me confrim which type of fiber patch cord I should choose?

Dear officer, I need a fibre patch cord as an extension cable to connect to my Fiber Bragg Grating sensor. The FBG sensor is FC/APC (male), and my device port is FC female.

I used two LC-FC Fibre Patch Cord connected in series, then connected to the FBG sensor and the fibre interrogator, respectively. However, I found the FBG signal disappear when I connect it to the Fiber Patch Cord. I do not know whether the FPC (e.g., parameter) is not suitable for my FBG sensor.

And could you please help me check can I continue to use this type of Fiber Patch Cord in my project? Or could you please recommend the new suitable Fiber Patch Cord to me? Thanks. The specifications of the FBG sensor and the FPC cable have been attached to the form.
LUNA-Data-Sheet-FBG-os1200-final.pdf (191.5 KB)
914S-2-5-0XXXX.pdf (56.9 KB)

I checked for a Male/Female extension cable, with either FC/APC connectors or the FC connectors, and we do not have a match. Maybe one of the engineers that have some experience with these cables or sensors can add to the post.

I would suspect that these multiple interconnections are causing problems. A number of different techniques for polishing the end of a fiber optic cable exist, and poor optical coupling will result if, for example, one attempts to mate an APC (Angle polished) connector with a non-APC type.

Minimizing the number of connections is also advisable, since each one causes some loss of optical signal and presents an opportunity for a connection fault; the cores of single modes fibers are only about 9 micrometers in diameter, so very little alignment is required to cause loss of signal.