DD281664A5 - DIELECTRIC COATING SYSTEM FOR OPTIMIZING THE TRANSMISSION AND LOCKING AREA OPTICAL MULTIPLEXER / DEMULTIPLEXER - Google Patents

Abstract

The invention relates to a dielectric layer system for optimizing the passband and stopband of optical multiplexers / demultiplexers. The inventive solution relates to the production of optical multiplexers / demultiplexers based on dielectric filters. The vapor deposition of the filters onto standardized specimens is known, but has the disadvantages that an optimal ratio between signal and attenuation can not be set, since both layer system and optical sources have tolerances. A coating form has been developed, which makes it possible to compensate for manufacturing tolerances and thus guarantees optimal transmission ratios. The newly designed layer system makes it possible to make the spectral behavior over the coated surface location-dependent. This applies to optical high, low and band pairs. {Multiplexer / Demultiplexer; Interference filter; Reduction filter; Wavelength; Optically transparent carrier material}

Description

For this 2 pages drawings

Field of application of the invention

The invention is for the production of dielectric filters for optical communication systems.

Characteristic of the known state of the art

Multiplexer / demultiplexer with interference filters, which are arranged on the boundary surfaces of a biconcave, optically transmissive body, are known per se (see EPC 68198, DE-OS 3346365). The disadvantages of this known solution are the insufficient accuracy of the parameters of the filter when combining filters with different parameters due to the different filter values and the custom-made for each substrate. The advantages of the known solution, such as the high flexibility with respect to the coupling to optical fibers, transmitter and receiver and easier manufacturability, are ensured.

Furthermore, optical multiplexer / demultiplexer with glued, separately produced interference filter !! known. The disadvantage of this solution is that the manufacturing variations in the manufacture of thin film packages can not be compensated.

Object of the invention

The aim of the invention is to develop economical, tunable and adjustable optical multiplexer / demultiplexer with interference filter, in which the insufficient accuracy of the filters are balanced when combining filters with different parameters of the filter with respect to the transmission wavelength and the optimal filter values,

Explanation of the essence of the invention

The object of the invention is to develop a multiplexer / demultiplexer in which optical interference filters are vapor-deposited on a carrier material in such a way that the optimum signal / damping ratio can be set and that the manufacturing tolerances which result during the production of thin-film packages, be compensated by the fact that the location of the coupling is variable.

Erfindungsgernäß the object is achieved in that by rotation of the substrate on the pallet during the sputtering process, a wedge-shaped Schichtsystcm is generated (Figure 2). The production of large numbers of pieces is economical, since the natural layer thickness wedge used in the evaporation plant is exploited and because of (n-D layers, for example in a 4-channel multiplexer (n = 4), all three interference packets are produced at the same time (Figure 3).

On the outer rim arise the thinnest (short-wave) systems, on the middle ring the middle and on the inner ring the thickest (long-wave) systems. This creates the wedge entirely by itself-from inside to outside. When using rectangular beams, the edges are adjusted to the wedge at the same time.

Since the layer systems are protected by the optical putty (epoxy resin), good long-term stability of the edge layer is guaranteed ¹ : (climatic and mechanical influences omitted).

Due to the optical symmetry of the outer media of the system (refractive index of putty and S: light beams are the same) very steep edges with not too large number of layers can be generated.

embodiment

FIG. 2 shows a wedge-shaped layer system for 4 channels.

In a suitable vapor deposition system (FIG. 3), the carrier material to be vapor-deposited, which is located on rigidly attached layer carriers, which in turn are fastened on a rotating surface, is coated. Rotationsο Rotation speed depends on the used steaming unit ur.d you type of layer system to be produced.

 - Jrch rotation of the substrate (Figure 3), a wedge-shaped layer system is generated. However, it proves necessary to carry out a test run before starting, to measure these samples and then produce the required layer system.

Tunable multiplexers / demultiplexers of any number of channels can be made, which have the advantage that the tolerances can be adjusted de / optical sources and thus favorable transmission conditions, d. H. Selection can be set. The optical sources can be adjusted to the right and left until the most favorable point for the selection is reached.

Claims (2)

1. Dielectric layer system for optimizing the transmission and blocking area optical multiplexer / demultiplexer, consisting of an optically transparent substrate with two mutually parallel surfaces, are provided on the optical reflection filter, the wave-dependent reflect one part of the incident light on them and the other part let through that the reflection filters are realized as bandpass filters or edge filters and the filters are tunable to different wavelengths, that the interference filters are vapor-deposited on prefabricated sample disks or specially prepared transparent bodies and brought to the substrate by means of suitable optical adhesive, characterized in that the interference filters be coated in a wedge shape by rotation of the substrate during the sputtering process. 2. Dielectric layer system according to claim 1, characterized in that manufacturing tolerances in the manufacture of the thin film package are thereby compensated by coating sufficiently large compensation surfaces.