Preparation of dual mode spectroscopic system for testing: Analysis of sample holder and investigation of intensity noise.

Absorption spectroscopy is combined with the principle of multiple wavelengths to develop a biomedical sensing mechanism, laid by two Fibre Bragg Gratings. It is essential to incorporate a sample holder in the setup in which the substances can be tested, necessitating its complete investigation without and with the holder, in both directions. The average losses of the fibre junctions are 0.