Narrow wavelength interval soa-pin and manufacturing method thereof

Abstract

The present application relates to the field of optical communication technology, and more particularly to a narrow wavelength interval SOA-PIN and a manufacturing method thereof, the manufacturing method comprising: dividing an optical path into a front optical path and a rear optical path with a SOA chip as a boundary; establishing the front optical path first and then the rear optical path when the SOA-PIN is coupled; establishing the front optical path through reverse bias characteristics of the SOA chip; the front optical path comprising a first collimating lens, an isolator, a second collimating lens and an optical port arranged in sequence; establishing the rear optical path through forward bias characteristics of the SOA chip; the rear optical path comprising a third collimating lens, a filter, a fourth collimating lens and a PIN chip arranged in sequence. The present application can take into account both yield and the demand for increasingly dense signal wavelengths.

Description

Technical Field

[0001] This invention relates to the field of optical communication device technology, and in particular to a narrow wavelength spacing SOA-PIN and its fabrication method. Background Technology

[0002] Traditional SOA-PIN coupling does not utilize the reverse-biased characteristics of the Semiconductor Optical Amplifier (SOA) chip; instead, it relies solely on the forward-biased characteristics of the SOA, establishing the rear optical path first and then the front optical path. The SOA must operate under forward bias to amplify, but this forward bias also results in significant broadband noise. Therefore, when only utilizing the forward bias of the SOA, the rear optical path must be established first, followed by the front optical path.

[0003] Traditional manufacturing methods utilize the noise light emitted by the SOA (Socketless Aperture System) during forward bias to couple this noise light into the PIN chip (PD chip), which then couples to the front optical path. However, during the establishment of the rear optical path, the filter mounting angle is strongly correlated with the wavelength of the transmitted light. Since the light emitted by the SOA is broadband noise, if the placement machine's precision is insufficient and the filter angle is incorrect, the light passing through the filter will experience wavelength drift and enter the PIN chip. The PIN chip responds to all wavelengths and cannot distinguish whether the wavelength passing through the filter is correct. Therefore, after the rear optical path is established, when attempting to establish the front optical path, if the correct signal wavelength is input from the front optical path, it is found that the signal wavelength has been completely or partially filtered out by the incorrectly angled filter. This necessitates rework, which involves an element of luck and results in a very low yield.

[0004] When the signal wavelengths of several SOA-PINs are widely spaced, if the filter only removes some of the signal wavelengths, it will affect the signal amplification effect and can still be used. However, if the filter removes all of the signal wavelengths, then the SOA-PIN will be completely unusable.

[0005] Therefore, how to overcome the shortcomings of the existing technology and how to balance the needs of yield and increasingly dense signal wavelengths is a problem that urgently needs to be solved in this technical field. Summary of the Invention

[0006] To address the above technical problems, this invention provides a narrow wavelength spacing SOA-PIN and its manufacturing method to balance the needs of yield and increasingly dense signal wavelengths.

[0007] This invention is implemented as follows:

[0008] In a first aspect, the present invention provides a method for fabricating a narrow wavelength spacing SOA-PIN, comprising:

[0009] The optical path is divided into a front optical path and a rear optical path, with the SOA chip as the boundary; during SOA-PIN coupling, the front optical path is established first, and then the rear optical path is established.

[0010] The front optical path is established using the reverse polarization characteristics of the SOA chip; the front optical path includes a first collimating lens, an isolator, a second collimating lens, and an optical port arranged sequentially.

[0011] The rear optical path is established by utilizing the positive bias characteristics of the SOA chip; the rear optical path includes a third collimating lens, a filter, a fourth collimating lens, and a PIN chip arranged sequentially.

[0012] In a preferred embodiment, dividing the optical path into a front optical path and a rear optical path with the SOA chip as the boundary specifically includes:

[0013] The SOA chip and the PIN chip are mounted to a preset position and gold wire bonded; the portion from the SOA chip to the optical port is divided into the front optical path; the portion from the SOA chip to the PIN chip is divided into the rear optical path.

[0014] In a preferred embodiment, establishing the front optical path using the reverse bias characteristics of the SOA chip specifically includes:

[0015] The isolator and the second collimating lens are assembled between the SOA chip and the optical port; wherein the isolator is on the side closer to the SOA chip, and the second collimating lens is on the side closer to the optical port;

[0016] Add the first and second signal beams to the optical port; reverse bias the SOA chip and couple it to the optical port. At this time, the SOA chip has a microamp-level response current output, and couple the first and second signal beams to the maximum. Solder and solidify the optical port.

[0017] The input of the first and second signal beams is continued, the SOA chip is kept reverse-biased, and the first collimating lens is coupled and solidified between the SOA chip and the isolator; the front optical path is established.

[0018] In a preferred embodiment, establishing the rear optical path using the forward bias characteristics of the SOA chip specifically includes:

[0019] The SOA chip is changed to forward bias, so that the first signal light and the second signal light are continuously input, and the filter is pre-aligned.

[0020] The third collimating lens is pre-coupled between the SOA chip and the filter, and the fourth collimating lens is pre-coupled between the filter and the PIN chip until the PIN chip has a microamp-level response current, and the response currents of the first signal light and the second signal light are both adjusted to the maximum.

[0021] Dispense adhesive and cure the filter sheet;

[0022] Couple the third collimating lens and the fourth collimating lens until the response current of the first signal light and the second signal light to the PIN chip both meet the requirements; apply adhesive to cure the third collimating lens and the fourth collimating lens; the rear optical path is now established.

[0023] In a preferred embodiment, the PIN chip is either flat or vertically mounted.

[0024] Secondly, the present invention provides a narrow wavelength spacing SOA-PIN, which is manufactured using the narrow wavelength spacing SOA-PIN manufacturing method as described in the first aspect, and includes a front optical path and a rear optical path, wherein the front optical path and the rear optical path are divided by an SOA chip.

[0025] In a preferred embodiment, the front optical path includes a first collimating lens, an isolator, a second collimating lens, and an optical port arranged sequentially; wherein, the first collimating lens is located on the side closer to the SOA chip, and the optical port is located on the side farther away from the SOA chip; the isolator and the second collimating lens are disposed between the first collimating lens and the optical port, with the isolator closer to the SOA chip and the second collimating lens closer to the optical port.

[0026] In a preferred embodiment, an adjustment ring is provided on the outer periphery of the optical port housing, and the optical port housing is fixed to the second collimating lens housing by the adjustment ring.

[0027] In a preferred embodiment, the rear optical path includes a third collimating lens, a filter, a fourth collimating lens, and a PIN chip arranged sequentially; wherein the third collimating lens is located on the side closer to the SOA chip, and the PIN chip is located on the side farther away from the SOA chip; the filter and the fourth collimating lens are disposed between the third collimating lens and the PIN chip, with the filter closer to the third collimating lens and the fourth collimating lens closer to the PIN chip.

[0028] In a preferred embodiment, the cross-section of the fourth collimating lens is trapezoidal, with the first right-angled surface of the fourth collimating lens facing the filter and the second right-angled surface facing the PIN chip; the light path from the filter to the fourth collimating lens is reflected on the inclined surface of the fourth collimating lens after passing through the first right-angled surface, and then passes through the second right-angled surface before reaching the PIN chip.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] 1. During the coupling process of an SOA-PIN, signal and noise coexist, making it impossible to distinguish between the coupled noise light and signal light. This invention divides the optical path into a front optical path and a rear optical path, using the SOA chip as the boundary. It also utilizes the forward and reverse bias characteristics of the SOA and adjusts the traditional coupling sequence from the rear optical path to the front optical path to the front optical path. The advantage is that the front optical path is established first, ignoring the noise influence of the SOA itself and coupling the actual signal light into the PIN chip. This method effectively suppresses noise light with signal light, ensuring that the light coupled into the PIN is only the useful real signal, thereby maximizing the amplification efficiency of the SOA-PIN.

[0031] 2. During the establishment of the front optical path, the presence of an isolator, which only allows light to pass through in the forward direction, necessitates that the first collimating lens be coupled before the isolator is installed. While the traditional forward-biased SOA chip manufacturing method can also be used, coupling occurs after the isolator is installed, resulting in refraction in the optical path and preventing optimal coupling efficiency between the optical port and the first collimating lens. This invention, by assembling the isolator first and then coupling the first collimating lens and the optical port during the establishment of the front optical path, optimizes the coupling efficiency of the front optical path.

[0032] 3. The mounting angle of the SOA-PIN filter is strongly correlated with the signal wavelength that can pass through it. Traditional SOA-PIN manufacturing methods have long relied on the precision of the pick-and-place machine. When the precision of the pick-and-place machine reaches its limit, the signal wavelength interval between each SOA-PIN becomes fixed. This invention is largely unaffected by the precision of the pick-and-place machine. The position and angle of any component in the rear optical path can be adjusted so that the angle of the filter precisely hits the upper and lower edge wavelengths of the required signal, supporting SOA-PINs with a signal wavelength interval of 0.1nm. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 A flowchart illustrating a method for fabricating a narrow wavelength-spaced SOA-PIN according to an embodiment of the present invention;

[0035] Figure 2 An extended flowchart of step 20 provided in an embodiment of the present invention;

[0036] Figure 3 An extended flowchart of step 30 provided in an embodiment of the present invention;

[0037] Figure 4 A side sectional view of the SOA-PIN device provided in an embodiment of the present invention;

[0038] Figure 5 A top view of the SOA-PIN device provided in an embodiment of the present invention;

[0039] Figure 6 The optical path diagram of the SOA-PIN device with the PIN chip mounted flat, provided in the embodiments of the present invention;

[0040] Figure 7 The optical path diagram of the vertically mounted PIN chip for the SOA-PIN device provided in the embodiments of the present invention;

[0041] Figure 8 This is a flowchart illustrating the coupling process of the SOA-PIN provided in an embodiment of the present invention.

[0042] Figure 9 This is a flowchart illustrating the coupling process of a traditional SOA-PIN.

[0043] Figure 10 The coupling principle diagram of the first collimating lens when establishing the front optical path of a traditional SOA-PIN. Detailed Implementation

[0044] In the description of this invention, the terms "inner", "outer", "longitudinal", "lateral", "upper", "lower", "left", "right", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and do not require that this invention must be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0045] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0046] It should be noted that, unless otherwise defined, the various features in the embodiments of the present invention can be combined with each other, all of which are within the protection scope of this application. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology and location descriptions used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the invention.

[0047] This invention addresses the challenges of yield improvement and increasingly dense signal wavelengths. The first key aspect is the utilization of the reverse-biased characteristics of the SOA chip. This chip, when reverse-biased, does not emit noise light and exhibits the characteristics of a photodiode (PD), thus acting as a PD to establish the front optical path. The second key aspect is the direct integration of the isolator and the second collimating lens onto the front optical path without coupling. The optical port and the first collimating lens are then coupled to maximize the actual signal. The third key aspect is the use of signal light to precisely target the upper and lower edges of the desired signal, ensuring both signal beams are equal (meaning neither upper nor lower wavelength is attenuated, and the parallel light angle is correct). When the signal beam is at its maximum, the optical path is established.

[0048] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0049] Example 1

[0050] Embodiment 1 of the present invention provides a method for fabricating a narrow wavelength spacing SOA-PIN, such as... Figure 1 As shown, for reference Figure 4 , Figure 5 , Figure 6 The fabrication method of this narrow wavelength spacing SOA-PIN includes the following steps.

[0051] Step 10: Divide the optical path into front optical path 1 and rear optical path 2, using SOA chip 106 as the boundary; during SOA-PIN coupling, first establish the front optical path 1, then establish the rear optical path 2. Specifically, dividing the optical path into front optical path 1 and rear optical path 2 using SOA chip 106 as the boundary includes: mounting SOA chip 106 and PIN chip 110 to preset positions and performing gold wire bonding; dividing the portion from SOA chip 106 to optical port 101 into the front optical path 1; and dividing the portion from SOA chip 106 to PIN chip 110 into the rear optical path 2.

[0052] Step 20: Establish the front optical path 1 using the anti-polarization characteristics of the SOA chip 106; the front optical path 1 includes a first collimating lens 105, an isolator 104, a second collimating lens 103, and an optical port 101 arranged sequentially. The second collimating lens functions to collimate the light emitted from the optical fiber in the front optical path. The first collimating lens functions to converge the collimated light in the front optical path into the SOA chip. The isolator functions to prevent noise light from the SOA chip itself from hitting the fiber end face and reflecting back into the SOA chip. The isolator is a unidirectional element, meaning it only allows light from the optical fiber to the SOA chip, preventing noise light from the SOA chip from entering the optical fiber.

[0053] Step 30: Establish the rear optical path 2 using the forward bias characteristics of the SOA chip 106; the rear optical path 2 includes a third collimating lens 107, a filter 108, a fourth collimating lens 109, and a PIN chip 110 arranged sequentially. The third collimating lens functions to collimate the light emitted from the SOA chip in the rear optical path. The fourth collimating lens functions to converge the collimated light in the rear optical path into the PIN chip. The filter functions to amplify the signal light carrying wavelength information from the front optical path after it has been amplified by the SOA chip, and then apply the filter to the rear optical path to act as a bandpass, allowing only the signal light of that wavelength to enter the PIN chip, while suppressing and filtering out noise light of other wavelengths emitted by the SOA chip itself.

[0054] Through the above steps, the SOA chip 105 is used as the boundary to divide the optical path into front optical path 1 and rear optical path 2. Simultaneously, utilizing the forward and reverse bias characteristics of the SOA, the traditional coupling sequence from rear optical path 2 to front optical path 1 is adjusted to a coupling sequence from front optical path 1 to rear optical path 2. The advantage is that front optical path 1 is established first, which can ignore the noise influence of the SOA itself, allowing the actual signal light to be coupled into the PIN chip 109. The SOA-PIN fabricated using this method supports signal wavelength spacing of less than 0.1 nm.

[0055] like Figure 2 As shown, for reference Figure 4 , Figure 5 , Figure 6In one specific embodiment of this preferred embodiment, step 20, which involves establishing the front optical path 1 using the reverse bias characteristics of the SOA chip 106, specifically includes the following steps:

[0056] Step 21: Assemble the isolator 104 and the second collimating lens 103 between the SOA chip 106 and the optical port 101; wherein the isolator 104 is on the side closer to the SOA chip 106, and the second collimating lens 103 is on the side closer to the optical port 101.

[0057] Step 22: Add the first signal light 201 and the second signal light 202 to the optical port 101; reverse bias the SOA chip 106 and couple it to the optical port 101. At this time, the SOA chip 106 has a microamp-level response current output, and couples the first signal light 201 and the second signal light 202 to the maximum, and solder and solidify the optical port 101.

[0058] Step 23: Continue the input of the first signal light 201 and the second signal light 202, keep the SOA chip 106 reverse biased, couple and solidify the first collimating lens 105 between the SOA chip 106 and the isolator 104; the front optical path 1 is established.

[0059] In the above process, the reverse bias characteristic of SOA chip 106 is used to establish front optical path 1; front optical path 1 of SOA-PIN is a dual collimating lens structure; the second collimating lens 103 can be directly assembled and cured during assembly without coupling.

[0060] like Figure 3 As shown, for reference Figure 4 , Figure 5 , Figure 6 In one specific embodiment of this preferred embodiment, step 30, which involves establishing the rear optical path 2 using the forward bias characteristics of the SOA chip 106, specifically includes the following steps:

[0061] Step 31: Change the SOA chip 106 to positive bias so that the first signal light 201 and the second signal light 202 are continuously input to pre-align the filter 108.

[0062] Step 32: Pre-couple the third collimating lens 107 between the SOA chip 106 and the filter 108, and pre-couple the fourth collimating lens 109 between the filter 108 and the PIN chip 110 until the PIN chip 110 has a microamp-level response current. Adjust the response currents of both the first signal light 201 and the second signal light 202 to their maximum. It should be noted that during the pre-coupling of the third and fourth collimating lenses, if... Figure 6 Regarding the optical path configuration, the third and fourth collimating lenses need to be pre-coupled; if... Figure 7 Regarding the optical path configuration, pre-coupling of the third collimating lens is sufficient; pre-coupling of the fourth collimating lens is unnecessary. This is because when the third collimating lens is optimally coupled, the response current generated by the PIN chip will display a current maximum coupling value. Adding the fourth collimating lens will further increase this response current. When the fourth collimating lens is optimally coupled, the response current of the PIN chip will be the maximum current.

[0063] Step 33: Apply adhesive and cure the filter 108.

[0064] Step 34: Couple the third collimating lens 107 and the fourth collimating lens 109 until the response currents of the first signal light 201 and the second signal light 202 to the PIN chip 110 both meet the requirements; apply adhesive to cure the third collimating lens 107 and the fourth collimating lens 109; the rear optical path 2 is now established. It should be noted that the first and second signal lights represent the upper and lower limits of the edge wavelengths, respectively. When the coupling angle is incorrect, either the upper limit wavelength or the lower limit wavelength will be weakened. Only when the photocurrents of the upper and lower limit wavelengths are balanced is the coupling angle considered correct. For example, if the parallel light emitted from the third collimating lens rotates too much clockwise, the upper limit wavelength will be weakened; if it rotates too much counterclockwise, the lower limit wavelength will be weakened. Keeping the angle within a certain range allows both edge wavelengths to pass through simultaneously.

[0065] In the above process, the forward bias characteristic of SOA chip 106 is utilized to establish the rear optical path 2. The PIN chip 110 can be either flat or vertically mounted. When the PIN chip 110 is flat, the optical path diagram is referenced. Figure 6 As shown, the cross-section of the fourth collimating lens 109 is trapezoidal at this time, and the PIN chip 110 is located below the fourth collimating lens 109. When the PIN chip 110 is vertically mounted, the optical path diagram is as follows: Figure 7 As shown, the fourth collimating lens 109 has a rectangular cross-section at this time, and the PIN chip 110 is located to the left of the fourth collimating lens 109. It should be noted that... Figure 6 The structure shown can save length space and achieve the goal of miniaturization.

[0066] In summary, the embodiments of the present invention have the following advantages: 1. During the coupling process of SOA-PIN, signal and noise coexist, and it is impossible to distinguish whether the coupled noise light or signal light is being coupled. The method of the present invention divides the optical path into a front optical path and a rear optical path with the SOA chip as the boundary. At the same time, it utilizes the forward and reverse bias characteristics of SOA and adjusts the traditional coupling sequence from the rear optical path to the front optical path to the front optical path. The advantage is that the front optical path is established first, which can ignore the noise influence of SOA itself and couple the real signal light into the PIN chip; this method can effectively suppress the noise light with the signal light to ensure that the light coupled into the PIN is a useful real signal, thereby maximizing the amplification efficiency of SOA-PIN. 2. During the establishment of the front optical path, because of the presence of the isolator, which can only allow light to pass through in the forward direction, the first collimating lens needs to be coupled before the isolator is assembled. If the traditional forward-biased SOA chip manufacturing method is used, coupling is possible, but because the optical port is coupled again after the isolator is assembled, the optical path after the isolator is assembled has already undergone refraction, and the optical port and the first collimating lens cannot actually achieve optimal coupling efficiency. This invention assembles the isolator first when establishing the front optical path, and then couples the first collimating lens and the optical port, which can achieve optimal coupling efficiency in the front optical path. 3. The mounting angle of the SOA-PIN filter is strongly correlated with the wavelength of the signal that can pass through it. Traditional SOA-PIN manufacturing methods have long relied on the precision of the pick-and-place machine. When the precision of the pick-and-place machine reaches its limit, the signal wavelength interval between each SOA-PIN is fixed. This invention is basically unaffected by the precision of the pick-and-place machine. The position and angle of any component in the rear optical path can be adjusted so that the angle of the filter precisely hits the upper and lower edge wavelengths of the required signal, supporting SOA-PINs with a signal wavelength interval of 0.1nm.

[0067] Example 2

[0068] Based on the method for fabricating a narrow wavelength spacing SOA-PIN provided in Example 1, this preferred embodiment 2 also provides a narrow wavelength spacing SOA-PIN, fabricated by the method of Example 1. (See reference) Figure 4 , Figure 5 , Figure 6 As shown, the SOA-PIN includes a front optical path 1 and a rear optical path 2, which are separated by the SOA chip 106.

[0069] In one specific embodiment of this preferred embodiment, the front optical path 1 includes a first collimating lens 105, an isolator 104, a second collimating lens 103, and an optical port 101 arranged sequentially. The first collimating lens 105 is located on the side closer to the SOA chip 106, and the optical port 101 is located on the side farther from the SOA chip 106. The isolator 104 and the second collimating lens 103 are disposed between the first collimating lens 105 and the optical port 101, with the isolator 104 closer to the SOA chip 106 and the second collimating lens 103 closer to the optical port 101. In another specific embodiment of this preferred embodiment, an adjustment ring 102 is provided on the outer periphery of the optical port 101 housing, and the adjustment ring 102 is used to fix the optical port 101 housing to the housing of the second collimating lens 103.

[0070] In one specific embodiment of this preferred embodiment, the rear optical path 2 includes a third collimating lens 107, a filter 108, a fourth collimating lens 109, and a PIN chip 110 arranged sequentially; wherein, the third collimating lens 107 is located on the side closer to the SOA chip 106, and the PIN chip 110 is located on the side farther away from the SOA chip 106; the filter 108 and the fourth collimating lens 109 are disposed between the third collimating lens 107 and the PIN chip 110, with the filter 108 closer to the third collimating lens 107 and the fourth collimating lens 109 closer to the PIN chip 110.

[0071] In one specific embodiment of this preferred embodiment, reference is made to Figure 6 As shown, when the PIN chip 110 is flat, the cross-section of the fourth collimating lens 109 is trapezoidal. The first right-angled surface of the fourth collimating lens 109 faces the filter 108, and the second right-angled surface faces the PIN chip 110. The light path from the filter 108 to the fourth collimating lens 109 is reflected on the inclined surface of the fourth collimating lens 109 after passing through the first right-angled surface, and then passes through the second right-angled surface before reaching the PIN chip 110. (Reference) Figure 7 As shown, when the PIN chip 110 is vertically mounted, the cross-section of the fourth collimating lens 109 is rectangular, and the PIN chip 110 is located to the left of the fourth collimating lens 109. The light path from the filter 108 to the fourth collimating lens 109 passes through the two parallel surfaces of the fourth collimating lens 109 and then hits the PIN chip 110.

[0072] Based on the above structure, this embodiment will further describe in detail the coupling process of the SOA-PIN provided by the present invention, and also describe in detail the coupling process of the traditional SOA-PIN, so as to better illustrate the improvement points of the present invention through comparison.

[0073] refer to Figure 8 The SOA-PIN coupling flowchart provided in this embodiment of the invention includes the following steps:

[0074] First step, refer to Figure 4 and Figure 5 SOA chip 106 and PIN chip 110 are mounted.

[0075] The second step is gold wire bonding. This process is not related to the present invention and will not be shown in the accompanying drawings or detailed descriptions.

[0076] Third step, refer to Figure 4 and Figure 5 The isolator 104 and the second collimating lens 103 are assembled.

[0077] Step 4, refer to Figure 4 , Figure 5 , Figure 6 and Figure 7 Two signal lights are added, namely the first signal light source 201 and the second signal light source 202, to the optical port 101; the SOA chip 106 is reverse-biased and coupled to the optical port 101. At this time, the SOA chip 106 has a microamp-level response current output, which couples the first signal light source 201 and the second signal light source 202 to the maximum, and then welds and solidifies 101.

[0078] Step 5: Continuously input two signal beams, reverse-bias the SOA chip 106, and couple and solidify the first collimating lens 105. Front optical path 1 is now established.

[0079] Step 6: SOA chip 106 is switched to positive bias, and the first signal light source 201 and the second signal light source 202 are continuously input; pre-alignment filter 108.

[0080] The seventh step involves pre-coupling the third collimating lens 107 and the fourth collimating lens 109 to the PIN chip 110, which provides a microampere-level response current, thereby adjusting the response current of both signal beams to their maximum.

[0081] Step 8: Apply adhesive and cure filter 108.

[0082] Step 9: Couple the third collimating lens 107 and the fourth collimating lens 109 until the response currents of the first signal light source 201 and the second signal light source 202 to the PIN chip 110 meet the requirements. Apply adhesive to cure the third collimating lens 107 and the fourth collimating lens 109. The optical path 2 is now complete.

[0083] refer to Figure 9 The traditional SOA-PIN coupling flowchart includes the following steps:

[0084] First step, refer to Figure 4 and Figure 5 SOA chip 106, filter 108, and PIN chip 110 are mounted.

[0085] The second step is gold wire bonding. This process is not related to the present invention and will not be shown in the accompanying drawings or detailed descriptions.

[0086] Third step, refer to Figure 4 , Figure 5 , Figure 6 and Figure 7 When SOA chip 106 is forward biased, it emits broadband noise light, which is used to couple the third collimating lens 107 and the fourth collimating lens 109 and then solidify them.

[0087] Step 4, refer to Figure 10 The SOA chip 106 is forward biased, and the noise light emitted by the beam quality analyzer 300 and the SOA chip 106 is used to couple and solidify the first collimating lens 105. Then, optical path 1 is established.

[0088] Fifth step: Assemble isolator 104.

[0089] The sixth step involves forward biasing the SOA chip 106, utilizing its forward bias amplification of the optical signal to couple the entire optical path, and coupling the missing optical port 101 and the second collimating lens 103 in the welding optical path, thereby maximizing the photocurrent of the PIN chip 110.

[0090] Step 7: If the coupling photocurrent in step 6 cannot meet the requirements, then start reworking from step 3.

[0091] Step 8: Add an adjustable light source and scan to see if the required signal wavelength range is met. If some signal light is filtered out, start reworking from step 3.

[0092] As can be seen from the traditional SOA-PIN coupling process, when using the traditional coupling method, the optical path 000B is established first. However, due to incorrect angle or insufficient precision of the filter 107 mounting, there is a probability that some signal light will be filtered out, and the coupled light will be noise light from the SOA chip 106. That is, the coupling wavelength is incorrect.

[0093] In the SOA-PIN coupling process provided in this embodiment of the invention, the method of the present invention utilizes the reverse bias characteristics of the SOA chip 106, first establishes the front optical path 000A, and uses dual signal light inputs 201 and 202. This avoids the possibility of any signal light being filtered out, and the wavelength is accurately within the required signal wavelength range. Furthermore, because the angle of the filter 107 can be finely adjusted according to the needs of the signal light after the front optical path is established, the angle accuracy of the filter 107 can be controlled very highly. The signal wavelengths amplified by filters with different wavelengths paired with different SOA-PINs can be spaced very narrowly.

[0094] In summary, the embodiments of the present invention have the following advantages: 1. During the coupling process of SOA-PIN, signal and noise coexist, and it is impossible to distinguish whether the coupled noise light or signal light is being coupled. The method of the present invention divides the optical path into a front optical path and a rear optical path with the SOA chip as the boundary. At the same time, it utilizes the forward and reverse bias characteristics of SOA and adjusts the traditional coupling sequence from the rear optical path to the front optical path to the front optical path. The advantage is that the front optical path is established first, which can ignore the noise influence of SOA itself and couple the real signal light into the PIN chip; this method can effectively suppress the noise light with the signal light to ensure that the light coupled into the PIN is a useful real signal, thereby maximizing the amplification efficiency of SOA-PIN. 2. During the establishment of the front optical path, because of the presence of the isolator, which can only allow light to pass through in the forward direction, the first collimating lens needs to be coupled before the isolator is assembled. If the traditional forward-biased SOA chip manufacturing method is used, coupling is possible, but because the optical port is coupled again after the isolator is assembled, the optical path after the isolator is assembled has already undergone refraction, and the optical port and the first collimating lens cannot actually achieve optimal coupling efficiency. This invention assembles the isolator first when establishing the front optical path, and then couples the first collimating lens and the optical port, which can achieve optimal coupling efficiency in the front optical path. 3. The mounting angle of the SOA-PIN filter is strongly correlated with the wavelength of the signal that can pass through it. Traditional SOA-PIN manufacturing methods have long relied on the precision of the pick-and-place machine. When the precision of the pick-and-place machine reaches its limit, the signal wavelength interval between each SOA-PIN is fixed. This invention is basically unaffected by the precision of the pick-and-place machine. The position and angle of any component in the rear optical path can be adjusted so that the angle of the filter precisely hits the upper and lower edge wavelengths of the required signal, supporting SOA-PINs with a signal wavelength interval of 0.1nm.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; under the concept of the present invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the present invention as described above. For the sake of brevity, they are not provided in detail; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for fabricating a narrow wavelength spacing SOA-PIN, characterized in that, include: The optical path is divided into a front optical path (1) and a rear optical path (2) with the SOA chip (106) as the boundary; the front optical path (1) is established first and the rear optical path (2) is established later during SOA-PIN coupling. The front optical path (1) is established by using the anti-polarization characteristics of the SOA chip (106); the front optical path (1) includes a first collimating lens (105), an isolator (104), a second collimating lens (103), and an optical port (101) arranged in sequence. The rear optical path (2) is established by the positive bias characteristics of the SOA chip (106); the rear optical path (2) includes a third collimating lens (107), a filter (108), a fourth collimating lens (109), and a PIN chip (110) arranged in sequence.

2. The method for fabricating a narrow wavelength spacing SOA-PIN according to claim 1, characterized in that, The division of the optical path into a front optical path (1) and a rear optical path (2) using the SOA chip (106) as the boundary specifically includes: The SOA chip (106) and the PIN chip (110) are mounted to a preset position and gold wire bonded; the portion from the SOA chip (106) to the optical port (101) is divided into the front optical path (1); the portion from the SOA chip (106) to the PIN chip (110) is divided into the rear optical path (2).

3. The method for fabricating a narrow wavelength spacing SOA-PIN according to claim 1, characterized in that, The establishment of the front optical path (1) using the reverse bias characteristics of the SOA chip (106) specifically includes: The isolator (104) and the second collimating lens (103) are assembled between the SOA chip (106) and the optical port (101); wherein the isolator (104) is on the side closer to the SOA chip (106), and the second collimating lens (103) is on the side closer to the optical port (101); Add the first signal light (201) and the second signal light (202) to the optical port (101); reverse bias the SOA chip (106) and couple it to the optical port (101). At this time, the SOA chip (106) has a microamp-level response current output, and couple the first signal light (201) and the second signal light (202) to the maximum, and solder and solidify the optical port (101). Continuously input the first signal light (201) and the second signal light (202), keep the SOA chip (106) reverse biased, couple and solidify the first collimating lens (105) between the SOA chip (106) and the isolator (104); the front optical path (1) is established.

4. The method for fabricating a narrow wavelength spacing SOA-PIN according to claim 3, characterized in that, The establishment of the rear optical path (2) through the forward bias characteristics of the SOA chip (106) specifically includes: The SOA chip (106) is changed to positive bias so that the first signal light (201) and the second signal light (202) are continuously input to pre-align the filter (108). The third collimating lens (107) is pre-coupled between the SOA chip (106) and the filter (108), and the fourth collimating lens (109) is pre-coupled between the filter (108) and the PIN chip (110) until the PIN chip (110) has a microamp-level response current, and the response currents of the first signal light (201) and the second signal light (202) are both adjusted to the maximum. Dispense adhesive and cure the filter (108); Couple the third collimating lens (107) and the fourth collimating lens (109) until the response current of the first signal light (201) and the second signal light (202) to the PIN chip (110) meets the requirements; apply adhesive to cure the third collimating lens (107) and the fourth collimating lens (109); the rear optical path (2) is established.

5. The method for fabricating a narrow wavelength spacing SOA-PIN according to any one of claims 1-4, characterized in that, The PIN chip (110) can be either flat or vertically mounted.

6. A narrow wavelength spacing SOA-PIN, manufactured using the method for manufacturing a narrow wavelength spacing SOA-PIN as described in any one of claims 1-5, characterized in that, It includes a front optical path (1) and a rear optical path (2), and the front optical path (1) and the rear optical path (2) are divided by the SOA chip (106).

7. The narrow wavelength spacing SOA-PIN according to claim 6, characterized in that, The front optical path (1) includes a first collimating lens (105), an isolator (104), a second collimating lens (103), and an optical port (101) arranged sequentially. The first collimating lens (105) is located on the side closer to the SOA chip (106), and the optical port (101) is located on the side away from the SOA chip (106). The isolator (104) and the second collimating lens (103) are arranged between the first collimating lens (105) and the optical port (101), with the isolator (104) closer to the SOA chip (106) and the second collimating lens (103) closer to the optical port (101).

8. The narrow wavelength spacing SOA-PIN according to claim 7, characterized in that, An adjustment ring (102) is provided on the outer periphery of the housing of the optical port (101), and the housing of the optical port (101) is fixed to the housing of the second collimating lens (103) by the adjustment ring (102).

9. The narrow wavelength spacing SOA-PIN according to claim 6, characterized in that, The rear optical path (2) includes a third collimating lens (107), a filter (108), a fourth collimating lens (109), and a PIN chip (110) arranged sequentially. The third collimating lens (107) is located on the side closer to the SOA chip (106), and the PIN chip (110) is located on the side away from the SOA chip (106). The filter (108) and the fourth collimating lens (109) are arranged between the third collimating lens (107) and the PIN chip (110), with the filter (108) closer to the third collimating lens (107) and the fourth collimating lens (109) closer to the PIN chip (110).

10. The narrow wavelength spacing SOA-PIN according to claim 9, characterized in that, The cross-section of the fourth collimating lens (109) is trapezoidal. The first right-angled surface of the fourth collimating lens (109) faces the filter (108), and the second right-angled surface of the fourth collimating lens (109) faces the PIN chip (110). The light path from the filter (108) to the fourth collimating lens (109) is reflected on the inclined surface of the fourth collimating lens (109) after passing through the first right-angled surface, and then passes through the second right-angled surface before heading towards the PIN chip (110).

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