The results of a range of experimental characterization exercises of interferometric noise for the case of a representative 2-D time-spreading wavelengthhopping optical code family are presented. Interferometric noise is evaluated at a data rate of 2.5 Gbits/s within an OCDMA network emulation test bed established utilizing fiber Bragg grating encoders/decoders. The results demonstrate that this form of noise introduces significant system power penalties and must be taken into consideration in any OCDMA network designs and implementations.