Processing method of sapphire source rod special for sapphire optical fiber drawing

Abstract

The present application relates to the field of sapphire crystal processing, in particular to a sapphire fiber drawing special sapphire source rod processing method, comprising the following steps: 1) crystal orientation control, control the orientation angle deviation within ±0.1°, ensure the C-axis parallelism of the rod; 2) rod extraction, extract φ20mm, length greater than 0.5m, perpendicularity less than 0.5mm rod; 3) end face cutting, control the rod length 51cm±1cm; 4) multi-stage grinding, control the diameter 2mm±0.05mm; 5) multi-stage polishing, control the end face roughness Ra less than 5μm; 6) cleaning and packaging. The method solves the problems of high-hardness and high-fragility super-long and super-thin sapphire crystal rod orientation deviation, diameter tolerance and perpendicularity control, realizes the efficient and high-consistency processing of high-hardness and high-fragility super-long and super-thin sapphire crystal rod (φ2mm±0.05mm, length≥0.5m, perpendicularity<0.5mm), and provides core material guarantee for fiber drawing.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sapphire crystal processing, in particular to a sapphire source rod processing method special for sapphire fiber drawing. BACKGROUND

[0002] Sapphire material is widely used in aerospace, military, semiconductor and other fields due to its excellent optical, physical and chemical properties. In recent years, with the development of laser technology, sapphire fiber as a new type of optical material has become an important candidate material for high-power fiber lasers due to its high thermal conductivity, high melting point and low Brillouin scattering coefficient. However, the existing sapphire fiber preparation process still has some problems, such as directional deviation, insufficient verticality of rod extraction, surface defects, etc., which directly affect the optical performance and mechanical strength of the fiber.

[0003] In the traditional sapphire source rod processing technology, laser heating base method is usually used to prepare tapered optical fiber. However, this method cannot meet the geometric precision requirements of large-size (more than 0.5 meters) source rods. In addition, the existing grinding and polishing technology often cannot simultaneously consider processing speed and surface quality, especially when processing small-size and high-precision sapphire rods, which is prone to edge collapse, fragmentation and other adverse processes. These problems seriously restrict the application and development of sapphire optical fiber.

[0004] Therefore, it is urgent to develop a new sapphire source rod processing technology special for sapphire fiber drawing to solve the problems of large directional angle deviation, excessive verticality of rod extraction, surface defects, etc. in the existing technology, while improving processing efficiency and product quality. By using crystal directional control, rod extraction parameter optimization, multi-stage grinding and polishing process innovation and other technical means, the crystal directional angle control precision can be effectively improved, and the diameter tolerance, verticality and end face roughness of the source rod can be reduced, thereby meeting the preparation requirements of high-quality sapphire optical fiber. SUMMARY

[0005] To effectively solve the problems existing in the above-mentioned prior art, the present application provides a sapphire source rod processing method special for sapphire fiber drawing, which realizes the processing technology of high-quality sapphire source rod through crystal directional control, rod extraction parameter optimization, multi-stage grinding and polishing process innovation. Through this innovative process, the directional deviation, diameter tolerance and verticality control problems of high-hardness and brittle super-long and super-thin sapphire crystal rods are solved, and high-efficiency and high-consistency processing of high-hardness and brittle super-long and super-thin sapphire crystal rods (φ2mm±0.05mm, length≥0.5m, verticality<0.5mm) is realized, which provides core material guarantee for fiber drawing.

[0006] A sapphire source rod processing method special for sapphire fiber drawing, comprising the following steps:

[0007] Step 1, crystal orientation control: use an X-ray diffractometer to accurately measure the C-axis direction of the sapphire crystal ingot, control the orientation angle deviation within ±0.1°, and ensure that the subsequent rod extraction is parallel to the C-axis through crystal face marking technology;

[0008] Step 2, rod extraction: use a dynamic cooling system, diamond composite coating rod cutter, vibration sensing suppression platform, real-time calibration of perpendicularity through laser-machine vision cooperative calibration system, extract φ20mm, length greater than 0.5m rod from sapphire crystal ingot, ensure that the rod perpendicularity is less than 0.5mm;

[0009] Step 3, end face cutting: use a gold wire cutting machine to cut off the head and tail defect area, the cutting amount is not less than 5mm, the final rod length is 51cm±1cm, the cutting parameters are wire speed 10-30m / s, tension 20-40N, cooling liquid flow 5-10L / min;

[0010] Step 4, multi-stage grinding of the outer circle: adopt multi-stage grinding process, including coarse grinding, semi-fine grinding and fine grinding three stages, control the final diameter tolerance within ±0.05mm;

[0011] Step 5, polishing: use nylon matrix embedded diamond abrasive brush for step-by-step polishing, speed 2500-4000rpm, feed speed 5-20mm / min, control single removal amount less than 0.01mm, end face roughness control in Ra less than 5μm;

[0012] Step 6, cleaning and packaging: use multi-stage ultrasonic cleaning, including deionized water cleaning, ethanol cleaning in turn, super pure nitrogen blowing clean and dry, then vacuum shockproof packaging, ensure the surface is not contaminated.

[0013] The step 4 includes:

[0014] Step 401, coarse grinding: use high-speed diamond grinding wheel grinder, grinding wheel granularity is #300-#400, feed speed 200-300mm / min, control grinding depth less than 0.1mm, realize target crystal rod diameter φ2.5mm±0.2mm.

[0015] Step 402, semi-fine grinding: use centerless grinding machine, grinding wheel granularity is #500, use longitudinal grinding method, feed speed 50-100mm / min, control grinding depth 0.01mm, target diameter φ2.1mm±0.1mm;

[0016] Step 403, fine grinding: use precision centerless grinding machine, grinding wheel granularity is #2000, feed speed 20-50mm / min, control grinding depth 0.002mm, finally realize sapphire source rod processing with diameter φ2.0mm±0.05mm, perpendicularity less than 0.5mm.

[0017] In step 5, polishing is performed using diamond abrasive grains with particle sizes gradually decreasing from coarse to fine in sequence, including:

[0018] Step 501: polishing is performed using F120 diamond abrasive grains (particle size: 106 μm ~ 125 μm) to remove large burrs and lines;

[0019] Step 502: polishing is performed using F400 diamond abrasive grains (particle size: 17 μm ~ 23 μm) to make the surface uniform;

[0020] Step 503: polishing is performed using F800 diamond abrasive grains (particle size: 6 μm ~ 12 μm) to make the surface smooth.

[0021] In step 1, the C-axis direction of the crystal is accurately measured by X-ray diffraction method, and the C-direction orientation angle deviation is controlled within ±0.1° by combining with the crystal face marking technology, which significantly improves the optical performance uniformity of the optical fiber and solves the problem of orientation deviation in the traditional process;

[0022] In step 2, the defects of traditional processing methods that are difficult to extract high aspect ratio and small verticality rods are overcome: through the synergistic effect of diamond composite coating rod extraction tool and vibration sensing suppression platform, the mechanical vibration generated during rod extraction is effectively controlled, combined with a dynamic cooling system, real-time suppression of cutting thermal stress is realized, and a laser-machine vision collaborative calibration system is used to realize synchronous calibration of the verticality;

[0023] Further, through the deep synergy of the vibration sensing suppression platform and the dynamic cooling system, the dynamic balance of the mechanical vibration field and the cutting temperature field is realized, which creates a stable physical environment foundation for the laser-machine vision collaborative calibration system, thereby improving the verticality calibration precision, and through the real-time feedback of the calibration system to the vibration suppression system and the cooling system to form a closed-loop control system, high-precision non-damage rod extraction is realized while ensuring the autonomous optimization and stable control of the verticality; through the efficient synergistic control of multiple systems, the technical difficulties of existing technologies, such as the deterioration of rod extraction verticality caused by cutting heat accumulation and mechanical vibration, and the difficulty in processing large aspect ratio crystal rods caused by high rod breaking rate, are successfully overcome; φ20mm, length greater than 0.5m rod is successfully extracted from sapphire crystal ingot, which greatly optimizes the optical fiber drawing efficiency and stability, while ensuring that the rod verticality is less than 0.5mm, effectively reducing the risk of fiber breakage during fiber drawing;

[0024] The step 4 overcomes the double difficulties of traditional external grinding technology in simultaneously ensuring the extremely fine diameter and extremely small diameter tolerance and the grinding speed and precision: for the extremely fine diameter and extremely small diameter tolerance of the fiber source rod, the processing difficulty of external grinding is extremely great: in order to realize the extremely fine diameter processing, a larger grinding wheel granularity and a feeding speed are required to realize a larger grinding depth, however, the larger grinding wheel granularity exists the risk of rod fracture caused by the accumulation of grinding mechanical stress and thermal stress, which leads to insufficient length of the source rod, and the processing precision and perpendicularity of the rod are difficult to ensure; in order to ensure the diameter precision and realize the requirement of extremely small tolerance, a smaller grinding wheel granularity and a feeding speed are required to ensure a smaller grinding depth and a higher processing precision, however, the smaller grinding wheel granularity faces the problems of difficult to reach the target diameter range and low processing efficiency;

[0025] The step 4 realizes the efficient and high-consistency processing of the super-long and super-fine sapphire crystal rod (φ2mm, length≥0.5m) by designing the external multi-stage grinding process, establishing the grinding target and grinding removal amount model of each grinding level, and optimizing the best special grinding wheel granularity, feeding speed, grinding depth and other grinding parameters of each grinding level, while ensuring extremely high precision (diameter tolerance within ±0.05mm) and maintaining small perpendicularity (less than 0.5mm), which solves the double difficulties of the existing technology in simultaneously ensuring the extremely fine diameter and extremely small diameter tolerance and simultaneously ensuring the grinding speed and precision;

[0026] The step 5 solves the inherent contradiction of “quality-efficiency” in the traditional single-stage diamond polishing process: when small granularity abrasive, low speed and slow feeding are adopted, the material removal rate is very low, which cannot effectively remove the initial damage layer of the end face; on the contrary, if large granularity abrasive, high speed and fast feeding are adopted, although the material removal rate can be improved, defects such as scratches and micro-cracks will be caused, which will lead to the deterioration of roughness; in addition, if the abrasive granularity and the polishing process parameters are not balanced, the end face roughness cannot be small;

[0027] Further, the step 5 adopts the diamond brush step-by-step polishing technology, accurately designs the granularity of each stage of abrasive, and realizes the end face roughness Ra less than 5μm by cooperating with the optimized process parameter control, effectively reduces the fiber optical transmission loss, overcomes the problem of difficult surface quality and crack control in the traditional process, and at the same time realizes the improvement of processing efficiency;

[0028] The method optimizes more than 50% of each index (such as diameter tolerance, perpendicularity, end face roughness, etc.) in the processing process through the precise control and optimization of the whole process, significantly improves the overall quality and precision of the sapphire source rod, and meets the geometric precision requirements of the large-size source rod, wherein:

[0029] 1) The orientation process ensures accurate crystal direction basis for subsequent processes, avoiding unevenness in subsequent processing caused by too large crystal direction difference;

[0030] 2) The rod extraction process provides a geometric precision basis for subsequent processes. The rod extraction diameter is small (φ20mm), reducing the subsequent grinding processing amount to achieve an extremely fine diameter. The rod extraction length is long (>0.5m), avoiding the risk of insufficient source rod length after end face cutting. The perpendicularity is small (<0.5mm), so that the outer circle grinding only needs to maintain the perpendicularity without correction, reducing the processing difficulty;

[0031] 3) The outer circle grinding adopts a multi-stage gradient grinding process, which realizes the target extremely fine diameter processing while ensuring extremely high diameter precision. By accurately designing the gradient grinding granularity, the small perpendicularity is maintained, avoiding the risk of excessive mechanical stress and source rod length shortage caused by a single coarse granularity;

[0032] 4) The polishing process adopts diamond brush step-by-step polishing technology, combined with accurate process parameter control, to realize the precise requirement of small end face roughness.

[0033] The close connection and close cooperation of each process form a complete optimization technology chain of "crystal direction reference-geometric pre-control-precision forming-surface optimization", which finally realizes the efficient and consistent processing of high-hardness and brittle super-long and super-fine sapphire source rods with small diameter (φ2mm), small diameter tolerance (within ±0.05mm), high length (length≥0.5m), and small perpendicularity (less than 0.5mm), providing core material support for optical fiber drawing.

[0034] The application provides a sapphire source rod processing method special for sapphire optical fiber drawing, which has the following beneficial effects compared with the prior art:

[0035] 1. The X-ray diffraction method combined with crystal face marking technology is adopted to realize accurate control of C direction (angle deviation within ±0.1°), which significantly improves the optical performance uniformity of optical fiber;

[0036] 2. The rod extraction process is optimized by using a vibration sensing suppression platform, a dynamic cooling system, and a laser-machine vision collaborative calibration system, which effectively controls mechanical vibration, cutting thermal stress, and perpendicularity, realizes lossless rod extraction of high length-diameter ratio (φ20mm, length greater than 0.5m) and small perpendicularity (less than 0.5mm), and greatly optimizes the efficiency and stability of optical fiber drawing, effectively reducing the risk of breakage in the optical fiber drawing process;

[0037] 3. In view of the stringent requirements for the minimum diameter of the source rod and the diameter tolerance, by optimizing the parameters of the multi-stage grinding process, the efficient and consistent processing of ultra-long and ultra-fine sapphire crystal rods (φ2mm, length≥0.5m) is realized under the premise of ensuring high processing precision (diameter tolerance within ±0.05mm) and maintaining small verticality of the rod (less than 0.5mm);

[0038] 4. By optimizing the parameters of the step-by-step polishing process, the end surface roughness Ra is less than 5μm, effectively reducing the optical fiber light transmission loss, effectively improving the processing efficiency, and overcoming the problem of difficult surface quality and defect control in traditional processes. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 The flowchart of the method is shown. DETAILED DESCRIPTION

[0040] Example 1

[0041] A sapphire fiber drawing special sapphire source rod processing method, the flowchart is shown as Figure 1 The specific steps are as follows:

[0042] Step 1, crystal orientation control: put the sapphire crystal ingot into the X-ray diffractometer for accurate determination of the C-axis direction, and the directional angle deviation is controlled within ±0.1°. The C-axis direction angle obtained by X-ray diffractometer is 30.0°, combined with the crystal face marking technology, to ensure that the subsequent rod extraction is parallel to the C-axis;

[0043] Step 2, rod extraction: using dynamic cooling system, cooling liquid flow is 5L / min, using diamond composite coating rod extraction tool, matched with vibration sensing suppression platform, φ20mm, length of 0.6m rod is extracted from single crystal ingot, through laser-machine vision cooperative calibration system real-time calibration verticality, ensure that the verticality of the rod is less than 0.5mm, through laser measurement, the verticality of the extracted rod is 0.48mm;

[0044] Step 3, end face cutting: using diamond wire cutting machine to cut off the head and tail defect area, cutting parameters are wire speed 20m / s, tension 25N, cooling liquid flow 5L / min, cutting amount is 9cm, the final rod length is 51cm, through measurement, the flatness of the cut end face is 0.02mm;

[0045] Step 4, outer circle multi-stage grinding: using multi-stage grinding process, including coarse grinding, semi-fine grinding and fine grinding three stages:

[0046] Step 401, rough grinding: using a high-speed diamond grinding wheel grinder, the grit size of the grinding wheel is #400, the feed speed is 250 mm / min, the control grinding depth is 0.08 mm, the target crystal bar diameter is φ2.5 mm±0.2 mm, and the diameter after grinding is φ2.45 mm through measurement;

[0047] Step 402, semi-fine grinding: using a centerless grinding machine, the grit size of the grinding wheel is #500, the longitudinal grinding method is used, the feed speed is 80 mm / min, the control grinding depth is 0.01 mm, the target diameter is φ2.1 mm±0.1 mm, and the diameter after grinding is φ2.08 mm through measurement;

[0048] Step 403, fine grinding: using a precision centerless grinding machine, the grit size of the grinding wheel is #2000, the feed speed is 30 mm / min, the control grinding depth is 0.002 mm, the target diameter is φ2.0 mm±0.05 mm, and the diameter after grinding is φ1.98 mm, and the perpendicularity is less than 0.5 mm;

[0049] Step 5, polishing: using a nylon-based diamond-embedded diamond abrasive brush for polishing, using diamond abrasive particles with particle sizes of F120, F400 and F800 for step-by-step polishing, the rotation speed is 3000 rpm, the feed speed is 10 mm / min, the control single removal amount is less than 0.01 mm, the control target end surface roughness Ra is less than 5 μm, and the end surface roughness Ra after polishing is 3.2 μm through measurement;

[0050] Step 6, cleaning and packaging: using multi-stage ultrasonic cleaning, using deionized water and ethanol for cleaning in turn, using ultra-pure nitrogen gas for blowing, cleaning and drying, and finally using a shockproof vacuum bag for packaging to ensure that the surface is not contaminated.

[0051] Example two

[0052] A sapphire source rod processing method special for sapphire fiber drawing, the specific steps are as follows:

[0053] Step 1, crystal orientation control: the sapphire crystal ingot is placed in an X-ray diffractometer for accurate determination of the C-axis direction, and the directional angle deviation is controlled within ±0.1°. The C-axis direction angle measured by the X-ray diffractometer is 29.8°, and combined with the crystal face marking technology, the subsequent rod extraction is ensured to be parallel to the C-axis;

[0054] Step 2, rod extraction: using a dynamic cooling system with a cooling liquid flow rate of 6 L / min, a diamond composite coated rod extraction tool, and a vibration sensing suppression platform, a φ20 mm, 0.6 m long rod was extracted from the single crystal ingot. The verticality was calibrated in real time by a laser-machine vision cooperative calibration system to ensure that the verticality of the rod was less than 0.5 mm. The verticality of the extracted rod was 0.45 mm as measured by laser measurement.

[0055] Step 3, end face cutting: using a diamond wire cutting machine, the head and tail defect areas were cut with a wire speed of 18 m / s, a tension of 28 N, and a cooling liquid flow rate of 6 L / min. The cutting amount was 8 cm, and the final rod length was 52 cm. The end face flatness after cutting was 0.03 mm as measured.

[0056] Step 4, multi-stage grinding of the outer circle: using a multi-stage grinding process, including coarse grinding, semi-fine grinding, and fine grinding:

[0057] Step 401, coarse grinding: using a high-speed diamond grinding wheel grinder, the grinding wheel grit was #300, the feed speed was 280 mm / min, and the control grinding depth was 0.09 mm. The target crystal rod diameter was φ2.5 mm ± 0.2 mm, and the diameter after grinding was φ2.48 mm as measured.

[0058] Step 402, semi-fine grinding: using a centerless grinder, the grinding wheel grit was #500, the longitudinal grinding method was used, the feed speed was 70 mm / min, the control grinding depth was 0.01 mm, the target diameter was φ2.1 mm ± 0.1 mm, and the diameter after grinding was φ2.07 mm as measured.

[0059] Step 403, fine grinding: using a precision centerless grinder, the grinding wheel grit was #2000, the feed speed was 40 mm / min, the control grinding depth was 0.002 mm, the target diameter was φ2.0 mm ± 0.05 mm, and the diameter after grinding was φ1.99 mm with a verticality of less than 0.5 mm.

[0060] Step 5, polishing: using a nylon-based diamond-embedded abrasive brush for polishing, diamond abrasive particles with particle sizes of F120, F400, and F800 were used for step-by-step polishing, the rotation speed was 3000 rpm, the feed speed was 12 mm / min, the control single removal amount was less than 0.01 mm, the control target end face roughness Ra was less than 5 μm, and the end face roughness Ra after polishing was 3.8 μm as measured.

[0061] Step 6, cleaning and packaging: using multi-stage ultrasonic cleaning, deionized water and ethanol were used for cleaning, ultra-pure nitrogen gas was used for blowing and cleaning, and finally, an anti-vibration vacuum bag was used for packaging to ensure that the surface was not contaminated.

[0062] Comparative Example 1

[0063] A sapphire fiber drawing special sapphire source rod processing method, the specific steps are as follows:

[0064] Step 1, crystal orientation control: put the sapphire crystal ingot into the X-ray diffractometer to measure the C-axis direction, and control the directional angle deviation within ±0.2°. The C-axis direction angle obtained by X-ray diffractometer measurement is 30.2°, combined with the crystal face marking technology, to ensure that the subsequent rod extraction is parallel to the C-axis;

[0065] Step 2, rod extraction: use diamond-coated rod extraction tool to extract φ30mm, 0.4m long rod from single crystal ingot, and the verticality of the extracted rod is 1.15mm measured by verticality measuring ruler;

[0066] Step 3, end face cutting: use diamond wire cutting machine to cut off the head and tail defect area, the cutting parameters are wire speed 15m / s, tension 23N, cooling liquid flow rate 5L / min, cutting amount 15cm, and the final rod length is 25cm, the end face flatness after cutting is 0.05mm measured;

[0067] Step 4, outer circle grinding: adopt two-stage grinding process, including coarse grinding and fine grinding two stages:

[0068] Step 401, coarse grinding: use high-speed diamond grinding wheel grinder, the grit size is #600, the feed speed is 300mm / min, the control grinding depth is 0.15mm, the target crystal rod diameter is φ5mm±0.5mm, and the diameter after grinding is φ5.35mm measured.

[0069] Step 402, fine grinding: use centerless grinding machine, the grit size is #1200, the feed speed is 100mm / min, the control grinding depth is 0.005mm, the target diameter is φ2.0mm±0.15mm, and the diameter after grinding is φ2.08mm, the verticality is 1.07mm.

[0070] Step 5, polishing: use nylon matrix embedded F320 diamond abrasive grain brush for polishing, the rotating speed is 3200rpm, the feed speed is 15mm / min, and the end face roughness Ra after polishing is 8.9μm measured;

[0071] Step 6, cleaning and packaging: use multi-stage ultrasonic cleaning, use deionized water and ethanol for cleaning in turn, use ultrapure nitrogen gas to blow clean and dry, finally use shockproof vacuum bag for packaging, to ensure that the surface is not contaminated.

[0072] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application. Although the present application has been described in detail with reference to the above examples, those skilled in the art should understand that the specific embodiments of the present application can still be modified or replaced equivalently without departing from the spirit and scope of the present application, and any modification or equivalent replacement without departing from the spirit and scope of the present application should be covered in the scope of the claims of the present application.

Claims

1. A method for processing a sapphire source rod dedicated to sapphire optical fiber drawing, characterized by, The method comprises the following steps: Step 1, crystal orientation control: using an X-ray diffractometer to accurately measure the C-axis direction of the sapphire crystal ingot, controlling the orientation angle deviation within ±0.1°, and ensuring that the subsequent rod extraction is parallel to the C-axis direction through crystal face marking technology; Step 2, rod extraction: using a dynamic cooling system, a diamond composite coating rod extraction tool, a vibration sensing suppression platform, and a laser-machine vision cooperative calibration system to real-time calibrate the perpendicularity, extracting a rod with a diameter of φ20 mm and a length of more than 0.5 m from the sapphire crystal ingot, and ensuring that the perpendicularity of the rod is less than 0.5 mm; Step 3, end face cutting: using a diamond wire cutting machine to cut off the head and tail defect areas, the cutting amount is not less than 5 mm, and the rod length is controlled to be 51 cm±1 cm; Step 4, multi-stage grinding of the outer circle: the outer circle is ground through a multi-stage grinding process, which includes three stages of rough grinding, semi-fine grinding and fine grinding, the target diameter of the rough grinding is φ2.5 mm±0.2 mm, the target diameter of the semi-fine grinding is φ2.1 mm±0.1 mm, and the target diameter of the fine grinding is φ2.0 mm±0.05 mm; Step 5, polishing: using a nylon matrix embedded with diamond abrasive grains to polish step by step, and controlling the end face roughness Ra of the rod to be less than 5 μm; Step 6, cleaning and packaging: using multi-stage ultrasonic cleaning, sequentially using deionized water cleaning, ethanol cleaning, nitrogen blowing cleaning and drying, and then vacuum shockproof packaging.

2. The method of processing a sapphire source rod for sapphire optical fiber drawing as claimed in claim 1, wherein, In step 3, the cutting parameters are: wire speed 10-30 m / s, tension 20-40 N, and cooling liquid flow rate 5-10 L / min.

3. The method of claim 1, wherein the sapphire source rod is a sapphire fiber drawing dedicated sapphire source rod. In step 4, the rough grinding adopts a high-speed diamond grinding wheel grinder, the used grinding wheel particle size is #300-#400, the feed speed is 200-300 mm / min, and the grinding depth is controlled to be less than 0.1 mm.

4. The method of claim 1, wherein the sapphire source rod is a sapphire fiber drawing dedicated sapphire source rod. In step 4, the semi-fine grinding adopts a centerless grinder, the used grinding wheel particle size is #500, the longitudinal grinding method is adopted, the feed speed is 50-100 mm / min, and the grinding depth is controlled to be 0.01 mm.

5. The method of claim 1, wherein the sapphire source rod is a sapphire fiber drawing dedicated sapphire source rod. In step 4, the fine grinding adopts a precision centerless grinder, the used grinding wheel particle size is #2000, the feed speed is 20-50 mm / min, and the grinding depth is controlled to be 0.002 mm.

6. The method of processing a sapphire source rod for sapphire optical fiber drawing as claimed in claim 1, wherein, In step 5, the step-by-step polishing specifically is: using diamond abrasive grains with particle sizes of F120, F400 and F800 for polishing in sequence.

7. The method of processing a sapphire source rod for sapphire optical fiber drawing as claimed in claim 1 or 6, wherein, In step 5, the step-by-step polishing rotation speed is 2500-4000 rpm, the feed speed is 5-20 mm / min, and the single polishing removal amount is controlled to be within 0.01 mm.

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