CN1492259A - Method for producing tunable optical fiber attenuator - Google Patents

Abstract

The method of producing tunable optical fiber attenuator for light communication network includes the steps of: preparing two glass substrates with transparent conducting film, painting a 5-10 micron thick mixture of photocured prepolymer and liquid crystal to constitue record layer, designing laser holographic optical path in laser holographic or computer holographic method to establish planar interference, to form diffraction grating and to make the liquid crystal grating element. The liquid crystal grating has electric field tunable diffraction characteristic, that is, altering the strength of the AC electric signal applied to the liquid crystal grating element can control the diffraction light strength passing through the grating element and reach the aim of attenuate light power and regulating the power of transmitted light signal in the channel. The attenuator has low insertion loss, high resolution, high linearity, high repeatability, great attenuation range, high attenuation precision, small device size and other high quality.

Description

The tunable optical fiber attenuator manufacture method

Technical field

The present invention relates to a kind of tunable optical fiber attenuator manufacture method of on-mechanical formula, belong to optical communication field.

Background technology

Tunable optical fiber attenuator is the important devices in DWDM communication system and the all-optical network, is used for regulating the power of each road signal power in the communication system, to guarantee system stability work.The aspect such as assessment, research and adjustment, correction that can be used for optical communication line, system.Optical attenuator is one of development passive device the earliest in the optical communication, and in passive device, its output is only second to devices such as connector, coupling mechanism.The methods of the mobile gradual change light absorption attenuator of the many employings of the variable optical attenuator product of Shi Yonging in the market, the shortcoming of this method is that attenuator is made difficulty, costs an arm and a leg.Vibration during simultaneously owing to attenuator work not only can be introduced bigger insertion loss to communication system, and can cause the instability of system loss.

Summary of the invention

Purpose of the present invention is made difficulty in order to overcome existing variable optical attenuator product because the employing mechanical type moves the attenuator that manufacture method causes of gradual change light absorption attenuator, expensive shortcoming, provide a kind of on-mechanical formula, low-power consumption, fast speed, be beneficial to the manufacture method of system's miniaturization and integrated new type of adjustable optical attenuator.

Technical scheme of the present invention is: a kind of manufacture method of variable optical attenuator is characterized in that the step of method is:

1) two glass substrates that are coated with conductive layer of preparation are irritated the recording layer that the potpourri of Photosetting macromolecule pre-polymerization material that 5-10 μ is arranged and liquid crystal constitutes in glass substrate;

2) design holographic light path with laser hologram technique, on recording layer, set up plane interference and form diffraction grating and make the liquid crystal grating element;

3) on the liquid crystal grating element, apply electric field, utilize holographic liquid crystal grating to have the electric field tunable performance, be added in the power that ac signal is regulated electric field on the liquid crystal grating element, reach adjusting optical signal transmissive power by changing diffraction loss by change.

The present invention is based on this brand-new device of making automatically controlled tunable holographic polymer dispersed liquid crystal material grating, substitute and adopt gradual change optical attenuation sheet at present, in optical communication system, realize low-power consumption, high precision, low insertion loss, high resolving power, the linearity and good reproducibility, the tunable attenuate light signal that adjustable extent is big.

Description of drawings

Fig. 1 is for making Polymer Dispersed Liquid Crystal sample box synoptic diagram;

Fig. 2 makes automatically controlled Polymer Dispersed Liquid Crystal grating synoptic diagram for laser hologram technique;

Decay incident optical power synoptic diagram when Fig. 3 is no-voltage;

Fig. 4 is the decay incident optical power synoptic diagram when voltage is arranged;

Decay incident optical power synoptic diagram when Fig. 5 surpasses a certain threshold value for voltage.

Embodiment

The implementation step of this method is: 1, preparation liquid crystal grating element, by shown in Figure 1, it comprises two glass substrates 1 that are coated with ITO conductive layer 2, in glass substrate 1, irritate the Photosetting macromolecule pre-polymerization material of 5_10 μ and the potpourri 4 (polymer dispersion liquid crystal materials of liquid crystal are arranged, be PDLC solution) recording layer that constitutes, PDLC solution two ends are equipped with spacer 3; 2, design holographic light path with laser hologram technique, set up plane interference and form diffraction grating and make the liquid crystal grating element on recording layer, by shown in Figure 2,5 is that coherent laser 1,6 is the interference fringe of coherent laser 2,7 for producing; 3, apply electric field on liquid crystal grating, under electric field action, the molecular orientation of liquid crystal has gradually from the disordered state unification to the trend along direction of an electric field.The size that applies electric field directly influences the index modulation degree of unified degree of liquid crystal molecular orientation and grating fringe, size according to the required decay design electric field of luminous power in the practical communication channel, and the power of timely adjustment electric field, reach the purpose of regulating optical signal transmissive power by changing diffraction loss.Shown in Fig. 3,4,5,8 is input signal, and 9 is output signal, 10 expression diffraction attenuations.Fig. 3 represents that no-voltage is done the time spent, and the diffraction attenuation effect is stronger, output signal a little less than.Fig. 4 represents that under the voltage effect, diffraction attenuation weakens, and the output signal luminous power increases, can be according to system's needs, and the size of design and control voltage changes output power.Fig. 5 then represents, when voltage surpasses certain threshold value, and liquid crystal droplet and polymer-matrix refractive index match, the grating disappearance, the input optical power signal directly passes device does not have power attenuation.

Claims (1)

1, a kind of variable optical attenuator manufacture method is characterized in that, the step of method is:

1) two glass substrates that are coated with conductive layer of preparation are irritated the recording layer that the potpourri of Photosetting macromolecule pre-polymerization material that 5-10 μ is arranged and liquid crystal constitutes in glass substrate;

2) design holographic light path with laser hologram technique, on recording layer, set up plane interference and form diffraction grating and make the liquid crystal grating element;

3) on the liquid crystal grating element, apply electric field, utilize holographic liquid crystal grating to have the electric field tunable performance, be added in the power that ac signal is regulated electric field on the liquid crystal grating element, regulate optical signal transmissive power by changing diffraction loss by change.

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