Multimode Silica Fiber Research Articles

Multimode Deposited Silica Waveguide and its Application to an Optical Branching Circuit

A fabrication procedure has been developed for multimode deposited silica waveguide (DS guide), consisting of uniform and thick glass layer formation for core and cladding, and amorphous Si mask film for reactive sputter etching. The embedded multimode DS guide with a square core cross section has a transmission loss of 1.3 dB/cm at 633 nm wavelength. Waveguide parameters, such as core dimension, refractive index, and index difference, are similar to those of a multi-mode silica fiber. A multimode optical branching circuit with eight output ports was demonstrated by the above fabrication procedure. Excess insertion loss was 2 dB.

Multimode deposited silica waveguide and its application to an optical branching circuit

A fabrication procedure has been developed for multimode deposited silica waveguide (DS guide), consisting of uniform and thick glass layer formation for core and cladding, and amorphous Si mask film for reactive sputter etching. The embedded multimode DS guide with a square core cross section has a transmission loss of 1.3 dB/cm at 633 nm wavelength. Waveguide parameters, such as core dimension, refractive index, and index difference, are similar to those of a multi-mode silica fiber. A multimode optical branching circuit with eight output ports was demonstrated by the above fabrication procedure. Excess insertion loss was 2 dB.

Fusion splices for optical fibers by discharge heating

A new type of electric discharge fusion splicing apparatus for optical fibers offering several advantages is developed and evaluated. An average splicing loss of 0.10 dB is obtained for step-index multimode silica fibers with a 60-microm core diameter. Tolerances in discharge energy, fiber misalignment, compression force and stroke length during fusion, and end face conditions are discussed experimentally. No accurate fiber axis adjustment is necessary in this apparatus. Mechanical strength of the splice is also excellent.

Measurements of wavelength dependence of group delay in a multimode silica fiber

The wavelength dependence of the group delay in a multimode silica fiber was determined from the wavelength-dependent phase shift of the sinusoidally modulated light transmitted by the fiber. When the lower-order modes were dominant in the modal power distribution, the measured dispersion at a wavelength of 830 nm was 0.90 ns/10 nm/km. When the launching conditions were changed to excite more of the higher-order modes, the measured dispersion decreased to 0.60 ns/10 nm/km, indicating that the material dispersion was compensated partially by the waveguide dispersion.