CN1049288C - Manufacturing method of self-focusing lens type tunable optical filter single-mode pigtail collimator - Google Patents

Abstract

The present invention relates to an optical fiber communication technology, which is particularly suitable for the manufacturing occasion of a single-mode tail fiber collimator in a tunable optical filter of a self-focusing lens, which is a key component in dense optical wavelength division multiplexing. The technology adjusts the distance and the coupling state between the single-mode tail fiber and the self-focusing lens until the return light detected by a monitoring device consisting of the single-mode fiber coupler and the optical power meter reaches the maximum value, and then the axial symmetry coupling state between the single-mode tail fiber and the self-focusing lens is achieved and fixed. The resonant cavity made by the method has better performance than the resonant cavity formed by the collimator made by the non-quantitative method for finding the reference by visible light.

Description

Manufacturing method of self-focusing lens type tunable optical filter single-mode pigtail collimator

The invention relates to an optical fiber communication technology, and is especially suitable for the production occasion of a single-mode pigtail collimator in a self-focusing lens Fabry-Perot tunable optical filter, a key component in intensive optical wavelength division multiplexing.

The self-focusing lens type Fabry-Perot resonant cavity is composed of a pair of P/4 self-focusing lenses with single-mode pigtails, and a dielectric high-reflection film is directly plated on the opposite end faces of the two self-focusing lenses to form a Fabry-Perot resonant cavity. This self-focusing lens is also a collimating focusing coupling element. An important factor affecting the performance of the self-focusing lens Fabry-Perot cavity tunable filter is the fabrication of the single-mode pigtailed collimator. Various single-mode pigtail collimators must first make the end face of the single-mode pigtail: insert the optical fiber into the ferrule body, glue and dry it, fix it with a metal clamp, and then grind and polish the end face on the fixture to ensure that the fiber The optical axis of the core is perpendicular to the end face of the fiber. The single-mode pigtail collimator used in the self-focusing lens type Fabry-Perot tunable optical filter is different in structure from the single-mode pigtail collimator for conventional coupling, because the interface of the former self-focusing lens is coated with a dielectric high Anti film. In the past, visible light (such as 632.8nm He-Ne red light) was commonly used to make single-mode fiber collimators with optical communication window wavelengths of 1.31 μm or 1.55 μm. Due to the difference between the working wavelength and the adjustment wavelength, considerable errors will be introduced, which will cause resonance The two collimators of the cavity cannot meet the requirements of axisymmetric coupling, or cannot achieve confocal coupling when forming a resonant cavity, which leads to the introduction of a certain incident angle in the cavity or the mismatch of the intra-cavity modes, which seriously affects the F-P cavity. Peak transfer characteristics and finesse. Regarding the self-focusing lens type Fabry-Perot tunable optical filter, many documents have been reported, such as H.Schmuck etc. "Low Loss SM Fiber-Pigtailed GRIN-Lens Fabry-PerotType Filter for widely Variable Free Spectral Range" ECOC89 -585, but the manufacturing method of the single-mode pigtail collimator has not been disclosed.

In view of the above-mentioned shortcomings in the prior art, the task of the present invention is to provide a method for manufacturing a single-mode pigtail collimator.

The technical solution of the present invention is that the single-mode pigtail collimator is an optical element, which is composed of a P/4 self-focusing lens and a single-mode optical fiber, and the coupling between the optical fiber and the lens is axisymmetric. Because the light emitted from the optical fiber is expanded into parallel light after passing through the P/4 lens, the two collimators can perform fiber-to-fiber and point-to-point coupling. Then dry it, fix it with a metal fixing card, and then grind and polish its end face on the fixture, and ensure that the fiber core axis is perpendicular to the end face of the fiber. The technical measure that the present invention takes is to directly adopt the light of the working wavelength of the collimator to adjust, utilize the equal reflection end face of the self-focusing lens, carry out the axisymmetric coupling between the optical fiber and the lens with the method of self-collimation, it is characterized in that: a. The light source, optical isolator, and single-mode fiber coupler are sequentially connected through single-mode fiber, the detection port of the optical power meter and the optical isolator are respectively connected on the same side of the single-mode fiber coupler, and the other side of the single-mode fiber coupler is connected to the single-mode tail Fiber connection; b. Fix the single-mode pigtail and the P/4 self-focusing lens with high-reflection film on the high-precision fine-tuning frame with clamps; c. Adjust the distance between the single-mode pigtail and the self-focusing lens Distance and coupling state, until the return light detected by the single-mode fiber coupler and optical power meter reaches the maximum value, then the axisymmetric coupling state between the single-mode fiber pigtail and the self-focusing lens is reached; d. Then use optical glue Or the metallized packaging process makes the pigtail and the self-focusing lens firmly combined.

The advantage of the present invention is that two single-mode pigtail collimators of the present invention can be used to form a Fabry-Perot resonant cavity after proper adjustment. The test results show that under the same conditions, the performance of the Fabry-Perot resonator made by this method is much better than that of the Fabry-Perot resonator made of the collimator made by the non-quantified method of finding the reference of visible light.

The accompanying drawings are as follows:

Accompanying drawing 1 schematic diagram of single-mode pigtail collimator

Figure 2 Schematic diagram of the end face of the single-mode pigtail

Accompanying drawing 3 is the schematic diagram of making and monitoring the collimator of the present invention

The implementation status of the present invention is explained below in conjunction with the accompanying drawings.

Figure 1 shows a single-mode pigtail collimator, which consists of a P/4 self-focusing lens 5 and a single-mode pigtail 4 bonded or metallized package. When making a single-mode pigtail collimator, the end face of the single-mode pigtail must be made first, as shown in Figure 2. The core of the single-mode fiber 10 is glued and inserted into the ferrule body 12, and then bonded and dried. Fix it, and then grind and polish its end face on the fixture. At this time, ensure that the optical axis of the fiber core is perpendicular to the end face of the fiber.

In Fig. 3, the light source 1, the optical isolator 2, and the single-mode fiber coupler 3 are sequentially connected through a single-mode fiber, and the detection port of the optical power meter 9 and the optical isolator 2 are respectively connected on the same side of the single-mode fiber coupler 3, and the single-mode The other side of the optical fiber coupler 3 is connected with the single-mode pigtail 4, and the single-mode pigtail 4 and the P/4 self-focusing lens 5 with the high reflection film 6 are clamped and fixed on the highly precise fine-tuning frame 7, 8 respectively by the clamp, Its adjustment method has been described in the technical solution section of this manual.

In this embodiment, the light source 1 adopts the MG9001A laser diode of Japan Anritsu Company; the optical isolator 2 adopts the online optical isolator WRIISO-PIS-155A commercialized by Wuhan Academy of Posts and Telecommunications; the single-mode fiber coupler 3 adopts the commercialized WRISTC-5 of Wuhan Academy of Posts and Telecommunications -2-155-09 type; the optical power meter 9 adopts the HP8153A type of Hewlett-Packard Company of the United States; the P/4 self-focusing lens 5 is the Japanese NSGXW18-S025-155 type; Dimensional trimmer.

Claims (1)

1. A method for making a self-focusing lens type tunable optical filter single-mode pigtail collimator, the single-mode pigtail collimator is composed of a P/4 self-focusing lens and a single-mode pigtail, First make the end face of the single-mode pigtail: insert the optical fiber into the ferrule body, glue and dry it, fix it with a metal fixing card, and then grind and polish the end face on the fixture, and ensure that the optical axis of the fiber core is perpendicular to the end face of the optical fiber. It is characterized by : a. The light source (1) and the optical isolator (2) and the single-mode fiber coupler (3) are sequentially connected through a single-mode fiber, and the detection port of the optical power meter (9) and the optical isolator are connected at the same time as the single-mode fiber coupler. One side is connected, and the other side of the single-mode fiber coupler is connected with the single-mode pigtail; b. The single-mode pigtail (4) and the self-focusing lens (5) of P/4 with high reflection film (6) are clamped and fixed on the high-precision fine-tuning frame (7), (8) respectively with a clamp; c. Adjust the distance and coupling state between the single-mode fiber pigtail (4) and the self-focusing lens (5) until the return light detected by the single-mode fiber coupler (3) and the optical power meter (9) reaches the maximum value, then Reach the axisymmetric coupling state between the single-mode pigtail and the self-focusing lens; d. Then, the pigtail (4) and the self-focusing lens (5) are firmly combined by optical glue or metallization encapsulation process.

Images