A marriage of optical fibre fabrication technology and LSI microfabrication technology gave birth to fibre-matched silica waveguides on silicon: thick glass layers of high-silica-content glass are deposited on silicon by flame hydrolysis, a method originally developed for fibre preform fabrication. Silica channel waveguides are then formed by photolithographic pattern definition processes followed by reactive ion etching. This ‘high silica (HiS) technology’ offers the possibility of integrating a number of passive functions on a single silicon chip, as well as the possibility of the hybrid integration of both active and passive devices on silicon. This paper reviews the NTT HiS technology and its application to integrated-optic components such as optical beam splitters, optical switches, wavelength-division multi/demultiplexers and optical frequency-division multi/demultiplexers. The clear and simple waveguide structures produced by the HiS technology make it possible to design and fabricate these components with high precision and excellent reproducibility.

Silica waveguides on silicon and their application to integrated-optic components

TUTORIAL REVIEW Silica waveguides on silicon and their application to integrated-optic components

A multifiber optical connector plug capable of realizing low reflection and low insertion loss, without using the refractive index matching material. The multifiber optical connector plug includes a connector plug member made of a plastic material, having a connecting facet on which endfaces of the optical fibers to be connected with other optical fibers are arranged in a transverse direction between the guide pin insertion holes, with the endfaces of the optical fibers projecting out of the connecting facet, the connecting facet being inclined with respect to an axial direction along optical axes of the optical fibers by an angle which is larger than a total reflection critical angle of light beams transmitted through the optical fibers. The connecting facet may have a flat surface shape or a convex ellipsoidal surface shape. A multifiber optical connector can be formed by a pair of such multifiber optical connector plugs with spring member for pressing the multifiber optical connector plugs toward each other in the axial direction and guide pins for aligning the multifiber optical connector plugs.

Multifiber optical connector plug with low reflection and low insertion loss

An optical fiber multi-ribbon and method for making the same is disclosed. The optical fiber multi-ribbon comprises N, where N is an integer greater than one, optical fiber ribbon members arranged in a common plane. Each of the N optical fiber ribbon members further comprise a plurality of optical fibers arranged in a planar array and an ultraviolet light curable primary matrix ribbonizing layer enveloping the plurality of optical fibers. The material forming the primary matrix ribbonizing layer of at least one of the N optical fiber ribbon members has a surface cure of at least about 80 percent. An ultraviolet light curable secondary matrix ribbonizing layer envelopes the primary matrix ribbonizing layers of the N optical fiber ribbon members. The secondary matrix ribbonizing layer material has a percent elongation to break greater than about 20 percent. The combination of the 80 percent surface cure of the primary matrix ribbonizing layers and the percent elongation to break greater than 20 percent of the secondary matrix ribbonizing layer provide an optical fiber multi-ribbon that has good handleability in terms of peeling of the secondary matrix ribbonizing layer from the primary matrix ribbonizing layer and good separation between the N optical fiber ribbons.

Optical fiber multi-ribbon and method for making the same

Thermally expanded core (TEC) fiber is expected to reduce fiber-to-fiber and fiber-to-laser diode connection loss This paper describes the characteristics of TEC fiber theoretically and experimentally We reveal theoretically that when fabricating TEC fiber the mode field diameter (MFD) is enlarged more effectively by increasing the heating temperature rather than the heating time In the 1300-1600/spl deg/C temperature range with heating times between 0 and 60 min, it is necessary to control the temperature accurately so that no deviation from the target temperature is more than /spl plusmn/30/spl deg/C This is in order to ensure that any connection loss caused by MFD mismatch is less than 01 dB We show experimentally that the propagation loss of TEC fiber is dependent on the heating region and wavelength by using a micro burner with a propane/oxygen flame Based on the relationship between the loss characteristics and the expanded MFD, we suggest a method for nondestructively measuring the MFD in TEC fibers

Characteristics of thermally expanded core fiber

A small plastic molded single-mode ten-fiber connector has been developed for high-count optical subscriber cables. The connector ferrule alignment mechanism is designed with a sufficient factor of safety to allow rough handling during connection. The ferrules are precisely aligned by alignment pins and guide sleeve. The fabricated connector, which has a cross section of just 4 mm * 6 mm, exhibited an average loss of 0.4 dB and reconnection time of less than 0.5 min. Connection loss does not change after over 1000 reconnections. >

Very small single-mode ten-fiber connector

Fabrication of an ultrahigh density cable is important, especially for subscriber loops. By using ultrahigh density cable, low cost optical transmission lines may be constructed. A multicore optical fiber1 100-200 μm in diameter is suitable. By using multicore fiber the cable diameter can be reduced drastically, compared with using ordinary monocore fiber. However ordinary multicore fiber is difficult to splice, because due to its circular construction, it is difficult to determine proper alignment. Splicing is difficult because the fibers must be rotated to achieve proper alignment. To overcome this, we developed a more easily spliced multicore fiber: bunch fiber.

New type of multicore fiber

This paper describes a newly developed low-loss demountable multifiber connector for ribbon-to-single optical fiber fan-out. The connector plugs contain special gathering parts that make a high-density arrangement for monocoated optical fibers. Using a multi-V-grooved mold, the optical fibers are accurately positioned and then a plastic formation process is adopted to form the plug. Plugs are precisely aligned by using two pins. An average connecting loss of 0.07 dB has been achieved in the stationary mode distribution with index matching. The change in connecting loss did not exceed ± 0.03 dB when the connector was subjected to heat cycles in a temperature range of -30-+60\deg C.

N.Kashima N.Kashima

Papers

Very small single-mode ten-fiber connector

New type of multicore fiber

New type of multicore fiber

Low-loss plastic molded optical multifiber connector for ribbon-to-single fiber fan-out

Fiber parameter dependence of skew in singlemode fiber ribbons