Light emitting chip and method of testing the same

Abstract

The embodiment of the present application discloses a light emitting chip and a testing method thereof. The method comprises: applying a test voltage to a light emitting area of the light emitting chip; wherein the light emitting chip has an optical film on a light emitting end face, the light emitting area of the light emitting chip is used for emitting a first light signal to the optical film under the action of the test voltage; the light emitting chip further comprises an absorbing area, and the absorbing area is used for absorbing a second light signal reflected by the optical film; a measuring circuit accessed through the absorbing area is used for detecting a current value of the absorbing area; wherein the current value has a corresponding relationship with the second light signal reflected by the optical film.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to semiconductor testing technology, and in particular, to a light emitting chip and a testing method thereof. BACKGROUND

[0002] With the increasingly wide application of semiconductor light devices, the optical performance requirements of semiconductor light emitting chips are also increasingly high. In the process of transmitting light emitted by a light emitting chip outward through the inside of the light emitting chip, reflection occurs at some positions, for example, reflection occurs when the emitted light passes through an optical film of the light emitting chip, or reflection occurs after the emitted light transmits through the optical film and enters an external light path. Since the reflected light will form crosstalk with the emitted light, the performance of the light emitting chip will be affected. SUMMARY

[0003] Therefore, embodiments of the present application provide a testing method of a light emitting chip, which comprises:

[0004] applying a test voltage to a light emitting region of the light emitting chip; wherein the light emitting chip has an optical film on a light emitting end face thereof, the light emitting region of the light emitting chip is configured to emit a first light signal to the optical film under the action of the test voltage, and the light emitting chip further comprises an absorption region configured to absorb a second light signal reflected by the optical film;

[0005] detecting a current value of the absorption region through a measurement circuit connected to the absorption region; wherein the current value has a corresponding relationship with the second light signal reflected by the optical film.

[0006] In some embodiments, the light emitting region of the light emitting chip comprises an active layer, and the active layer comprises at least one section, and different sections of the active layer have different light emitting wavelengths.

[0007] In some embodiments, the method further comprises:

[0008] adjusting a film quality parameter of the optical film according to the current value;

[0009] After adjusting the film quality parameter, the current value is re-detected until the current value meets a first predetermined current range.

[0010] In some embodiments, the film quality parameter of the optical film comprises at least one of the following:

[0011] a thickness of the optical film;

[0012] a reflectivity of the optical film; and a uniformity of the optical film.

[0013] In some embodiments, the light emitting chip further comprises an optical lens and an optical fiber having an optical fiber end face, and the method further comprises:

[0014] According to the current value, the positional relationship between the optical film, the optical lens and the fiber end face is adjusted; wherein, the first light signal emitted by the light-emitting area reaches the fiber end face through the optical lens and is reflected to the absorption area at the fiber end face, and the absorption area is also used to absorb the third light signal reflected by the fiber end face.

[0015] After adjusting the positional relationship, the current value is re-detected until the current value meets the second predetermined current range.

[0016] In some embodiments, adjusting the positional relationship between the optical film, the optical lens, and the fiber end face according to the current value includes: adjusting the positional relationship between the optical lens and the fiber end face according to the current value; wherein the optical film and the optical lens have a fixed positional relationship.

[0017] In some embodiments, adjusting the positional relationship between the optical film, the optical lens, and the optical fiber according to the current value includes: adjusting the positional relationship between the optical lens and the optical film according to the current value; wherein the optical film and the end face of the optical fiber have a fixed positional relationship.

[0018] In some embodiments, the positional relationship includes:

[0019] Distance relationship; and / or

[0020] Angular relationship.

[0021] In some embodiments, including:

[0022] The light-emitting area has an optical film on its light-emitting end face, and the light-emitting area of ​​the light-emitting chip is used to emit a first light signal to the optical film under the action of the test voltage;

[0023] The absorption region, located on the same optical path as the light-emitting region and the optical film, is used to absorb the second optical signal reflected by the optical film.

[0024] In some embodiments, the light-emitting chip further includes:

[0025] An optical lens and an optical fiber are located on the same optical path as the optical film; the optical fiber further includes an optical fiber end face; wherein the first optical signal emitted by the light-emitting region passes through the optical lens to the optical fiber end face and is reflected to the absorption region at the optical fiber end face, and the absorption region is also used to absorb the third optical signal reflected by the optical fiber end face.

[0026] In the embodiment of the present application, the first light signal emitted is reflected from the optical film by applying a test voltage to the light emitting chip, and the current value corresponding to the reflected second light signal is detected through the absorption area, so as to achieve the purpose of detecting the crosstalk light caused by reflection. In this way, the structure of the light emitting chip can be adjusted, so as to reduce the influence of crosstalk light and improve the performance of the light emitting chip. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 A flow chart of a test method of a light emitting chip provided in the embodiment of the present application is provided.

[0028] Figure 2 A light emitting chip provided in the embodiment of the present application is provided.

[0029] Figure 3 A flow chart of another test method of a light emitting chip provided in the embodiment of the present application is provided.

[0030] Figure 4 A flow chart of another test method of a light emitting chip provided in the embodiment of the present application is provided.

[0031] Figure 5 A test principle schematic diagram of a light emitting chip provided in the embodiment of the present application is provided.

[0032] Figure 6 A test principle schematic diagram of a light emitting chip and fiber coupling provided in the embodiment of the present application is provided.

[0033] Figure 7 A test principle schematic diagram of another light emitting chip provided in the embodiment of the present application is provided.

[0034] Figure 8 A test principle schematic diagram of another light emitting chip and fiber coupling provided in the embodiment of the present application is provided. DETAILED DESCRIPTION

[0035] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the accompanying drawings. The preferred embodiments of the present application are shown in the drawings. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present application is more thorough and comprehensive.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terminology used in the specification of the present application is only for the purpose of describing specific embodiments and is not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0037] The embodiment of the present application provides a testing method of a light emitting chip, as shown in the figure, the method comprises: Figure 1

[0038] Step S101, a testing voltage is applied to a light emitting area of the light emitting chip; wherein the light emitting chip has an optical film on a light emitting end face of the light emitting chip, the light emitting area of the light emitting chip is used for emitting a first light signal to the optical film under the action of the testing voltage; the light emitting chip further comprises an absorbing area, the absorbing area is used for absorbing a second light signal reflected by the optical film;

[0039] Step S102, a current value of the absorbing area is detected by a measurement circuit accessed by the absorbing area; wherein the current value has a corresponding relationship with the second light signal reflected by the optical film.

[0040] The semiconductor light emitting chip can be composed of two parts including a light emitting area and an absorbing area, the upper surfaces of the light emitting area and the absorbing area have P-face electrodes, the lower surface of the P-face electrode can be sequentially an upper cladding layer, an upper confinement layer, an active layer, a lower confinement layer, a lower cladding layer, a semiconductor substrate and an N-face electrode. The P-face electrode of the light emitting area is connected with one end of a voltage testing module, and the N-face electrode of the light emitting area is connected with the other end of the voltage testing module. The end face of the light emitting area far from the absorbing area is further plated with an optical film, the optical film can be an antireflection film, which is used for improving the transmittance of the light emitted by the light emitting chip. The voltage testing module applies a fixed voltage to the light emitting area, and the light emitting area emits light to the direction of the optical film under the action of the voltage testing module, but part of the light emitted by the light emitting area is reflected back as reflected light when passing through the optical film. The part of the reflected light is amplified when returning to the light emitting area of the chip as crosstalk light. The P-face electrode of the absorbing area is connected with a current measurement circuit module, and the N-face electrode of the absorbing area is also connected with the current measurement circuit module. The absorbing area absorbs the part of the crosstalk light and causes the change of the photoelectric current, and the current value of the current measurement circuit module accessed by the absorbing area is used for reflecting the change of the current caused by the part of the crosstalk light.

[0041] In the case that other internal conditions of the light emitting chip are unchanged, the quality of the optical film of the light emitting area corresponds to the size of the reflected light, the size of the reflected light corresponds to the size of the crosstalk light, and the size of the crosstalk light corresponds to the current value of the absorbing area.

[0042] For example, the better the quality of the optical film of the light emitting area is, that is, the higher the transmittance and the lower the reflectance of the optical film are, and thus the less the reflected light after the same light beam passes through the optical film. The less the emitted light is, the less the amplified light beam is when returning to the light emitting area of the chip, that is, the less the crosstalk light is. Because the crosstalk light enters the absorbing area, the crosstalk light is absorbed by the absorbing area. The absorbing of the crosstalk light by the absorbing area causes the change of the photoelectric current, and the less the crosstalk light is, the smaller the change of the photoelectric current is, and the smaller the value of the current meter in the current testing circuit is. ​

[0043] In summary, the quality of the optical film can be directly corresponded to the value of the ammeter, for example, the better the quality of the optical film, the smaller the value of the ammeter.

[0044] The worse the quality of the optical film, the more crosstalk light formed, and this part of crosstalk light consumes the carriers of the light emitting part in the chip, thereby causing changes in the performance of the chip, such as the stability of the light power, the wavelength of the emitted light, the modulation performance, or the spectral flatness, and therefore monitoring the quality of the optical film has very important practical significance. The monitoring method of reflecting the quality of the optical film by the size of the current value is simple and direct, and whether the optical film has been formed on the light emitting chip or in the real-time process of plating the optical film on the light emitting film, the quality of the optical film can be monitored by observing the size of the current value using the method of the present application.

[0045] In some embodiments, as shown in Figure 2 The light emitting region 101 of the light emitting chip 100 includes an active layer 103; the active layer 103 includes at least one section, and the light emitting wavelengths of different sections of the active layer are different.

[0046] The light emitted by the light emitting chip is generated by amplified spontaneous emission generated by the recombination of electrons and holes in the active layer of the light emitting chip. The active layer materials in the light emitting region and the absorption region can be the same or different, for example, the active layer materials of the light emitting region and the absorption region can use the same material and have the same energy band gap, at which time the active layer can be considered as a whole section. The active layer materials of the light emitting region and the absorption region can also use different materials, for example, the energy band gap of the active layer material of the light emitting region can be greater than the energy band gap of the active layer material of the absorption region, at which time the active layer is two sections. The active layer of the light emitting region can also be divided into two sections and more than two sections, and by filling different energy band gap materials in different sections, the light emitting region emits two or more different wavelengths of light, at which time the light emitting chip is a multi-section light emitting chip.

[0047] In some embodiments, as shown in Figure 3 The method further includes:

[0048] Step S103, adjusting a film quality parameter of the optical film according to the current value;

[0049] Step S104, after adjusting the film quality parameter, re-detecting the current value until the current value meets a first predetermined current range.

[0050] The size of the current has a corresponding relationship with the quality of the optical film, for example, the smaller the current value, the stronger the light transmittance of the optical film, and the better the quality of the optical film. When the light transmittance of the optical film is within the required range, for example, 99%, when the light transmittance of the optical film is greater than or equal to 99%, the current value is not a fixed value but a certain range, which is referred to as a first predetermined current range.

[0051] The first predetermined current range can be used to evaluate the quality of the optical film inversely, for example, when the light emitting area of the coated light emitting chip is connected to a fixed voltage, if the current value measured at the absorption area is within the first predetermined current range, the light emitting chip is marked as a qualified product; if the current value measured at the absorption area is not within the first predetermined current range, the light emitting chip is marked as a unqualified product.

[0052] The first predetermined current range can also be used to process the unqualified light emitting chip in a rework process, if the current value exceeds the first predetermined current range, the film quality parameters of the optical film can be adjusted, the current value is re-detected until the detected current is within the first predetermined current range, and the light emitting chip is upgraded from an unqualified product to a qualified product after the adjustment.

[0053] In some embodiments, the film quality parameters of the optical film include at least one of:

[0054] The thickness of the optical film;

[0055] The refractive index of the optical film;

[0056] The quality of the optical film is determined by the film quality parameters of the optical film, for a single layer optical film, when the optical film has media on both sides, the thickness of the optical film is an odd multiple of 1 / 4 wavelength and the refractive index n of the optical film is (n1*n2) 1 / 2 , where n1 and n2 are the refractive indices of the media on both sides of the optical film, n1 and n2 can be the same or different, when the optical film satisfies the above conditions, the stronger the transmittance of the optical film.

[0057] In some embodiments, as shown in Figure 4 , the light emitting chip further comprises an optical lens and an optical fiber, the optical fiber has an optical fiber end face; the method further comprises:

[0058] Step S105, adjusting the positional relationship between the optical film, the optical lens and the optical fiber end face according to the current value; wherein the first light signal emitted by the light emitting area passes through the optical lens to the optical fiber end face, and is reflected to the absorption area at the optical fiber end face, and the absorption area is also used to absorb the third light signal reflected by the optical fiber end face;

[0059] Step S106, after adjusting the positional relationship, re-detecting the current value until the current value meets a second predetermined current range.

[0060] In some embodiments, the light emitting chip can be fiber coupled with an optical lens and an optical fiber. The optical fiber can be one optical fiber or a bundle of optical fibers. The optical fiber has an optical fiber end face. Under the action of a fixed test voltage, the light emitting region emits light toward the optical film, and the light first passes through the optical lens, which can be a collimating lens, for example, to transform the dispersed light beam emitted by the light emitting chip into a parallel light beam, and the parallel light beam is coupled into the optical fiber. The optical lens can also be a combination of a collimating lens and a converging lens, which first transforms the dispersed light beam emitted by the light emitting chip into a parallel light beam, and then converges and couples the parallel light beam into the optical fiber. In some embodiments, the optical lens can also be a combination of multiple collimating lenses, converging lenses, and other lenses.

[0061] When the light beam emitted by the light emitting region passes through the optical lens to the optical fiber end face, part of the light beam is reflected back by the optical fiber end face as reflected light. This part of the reflected light is amplified when returning to the light emitting region of the chip as crosstalk light, which is absorbed by the absorption region when entering the absorption region. The absorption of crosstalk light by the absorption region causes a change in photocurrent, and the fewer crosstalk lights, the smaller the change in photocurrent, which is reflected in the current test circuit as a smaller value of the ammeter.

[0062] The coupling efficiency of the light emitting chip, the optical lens, and the optical fiber corresponds to the amount of light beam reflected back by the optical fiber end face from the light beam emitted by the light emitting chip. For example, the higher the coupling efficiency of the light emitting chip, the optical lens, and the optical fiber, the less the amount of light beam reflected back by the optical fiber end face, which is reflected in the current test circuit as a smaller value of the ammeter.

[0063] The coupling efficiency of the light emitting chip, the optical lens, and the optical fiber corresponds to the positional relationship between the light emitting chip, the optical lens, and the optical fiber. For example, when the coupling efficiency of the optical fiber is greater than or equal to the target coupling efficiency value, the current value is not a fixed value but within a certain range, which is recorded as a second predetermined current range.

[0064] For example, after the positional relationship between the light emitting chip, the optical lens, and the optical fiber is adjusted, if the measured current value is within the second predetermined current range, the coupling efficiency of the light emitting chip, the optical lens, and the optical fiber is above the target efficiency value, and it is determined that the optical fiber coupling is successful.

[0065] For example, when the positional relationship between the light emitting chip, the optical lens and the optical fiber is adjusted, if the measured current value is not within the second predetermined current range, the coupling efficiency of the light emitting chip, the optical lens and the optical fiber is below the target efficiency value, and it is determined that the optical fiber coupling is unsuccessful. At this time, the positional relationship between the light emitting chip, the optical lens and the optical fiber can be re-adjusted, and the current value can be re-detected until the current value meets the second predetermined current range, and it is determined that the optical fiber coupling is successful at this time.

[0066] In some embodiments, the adjusting the positional relationship between the optical film, the optical lens and the optical fiber according to the current value comprises: adjusting the positional relationship between the optical lens and the optical fiber according to the current value; and wherein the optical film and the optical lens have a fixed positional relationship.

[0067] In some embodiments, the method of adjusting the positional relationship between the light emitting chip, the optical lens and the optical fiber can be that the positional relationship between the optical film of the light emitting chip and the optical lens is fixed first, and then the positional relationship between the optical lens and the optical fiber is adjusted according to the current value returned by the current detection circuit.

[0068] In some embodiments, the adjusting the positional relationship between the optical film, the optical lens and the optical fiber according to the current value comprises: adjusting the positional relationship between the optical lens and the optical film according to the current value; and wherein the optical film and the optical fiber have a fixed positional relationship.

[0069] In some embodiments, the method of adjusting the positional relationship between the light emitting chip, the optical lens and the optical fiber can be that the positional relationship between the optical film of the light emitting chip and the optical lens is fixed first, and then the positional relationship between the optical lens and the optical fiber is adjusted according to the current value returned by the current detection circuit.

[0070] In some embodiments, the positional relationship comprises:

[0071] a distance relationship; and / or

[0072] an angle relationship.

[0073] The positional relationship between the light emitting chip, the optical lens and the optical fiber includes but is not limited to a distance relationship and / or an angle relationship between the light emitting chip and the optical lens, and a distance relationship and / or an angle relationship between the optical lens and the optical fiber.

[0074] In some embodiments, the distance relationship between the light-emitting chip and the optical lens can be the vertical distance from the center point of the light-emitting surface of the light-emitting chip to the center point of the optical lens; the distance relationship between the optical lens and the optical fiber can be the vertical distance from the center point of the optical lens to the center point of the end face of the optical fiber.

[0075] In some embodiments, the angular relationship between the light-emitting chip and the optical lens can be the angle between the line connecting the center point of the light-emitting surface of the light-emitting chip to the center point of the optical lens and the vertical line perpendicular to the light-emitting surface and passing through the center point of the light-emitting surface; the angular relationship between the optical lens and the optical fiber can be the angle between the line connecting the center point of the optical lens and the center point of the optical end face and the vertical line perpendicular to the center point of the optical lens.

[0076] In some embodiments, such as Figure 5 As shown, it includes:

[0077] The light-emitting area 101 has an optical film 104 on its light-emitting end face. The light-emitting area 101 of the light-emitting chip 100 is used to emit a first light signal to the optical film 104 under the action of the test voltage.

[0078] Absorption region 102, located on the same optical path as the light-emitting region 101 and the optical film 104, is used to absorb the second optical signal reflected by the optical film 104.

[0079] A semiconductor light-emitting chip can consist of two parts: a light-emitting region and an absorption region. A voltage testing module is connected to the light-emitting region. An optical film, which can be an anti-reflection film, is also coated on the end face of the light-emitting region furthest from the absorption region to improve the transmittance of the light emitted by the chip. The test voltage module applies a fixed voltage to the light-emitting region. Under the action of the test voltage module, the light-emitting region emits light towards the optical film, but a portion of the light emitted by the light-emitting region is reflected back as it passes through the optical film, becoming reflected light.

[0080] Because the light-emitting region, the absorption region, and the optical film are located on the same optical path, the absorption region can absorb the reflected light from the optical film.

[0081] In some embodiments, such as Figure 6 As shown, the light-emitting chip further includes:

[0082] An optical lens 301 and an optical fiber 302 are located on the same optical path as the optical film 104; the optical fiber 302 further includes an optical fiber end face 303; wherein, the first optical signal emitted by the light-emitting region 101 passes through the optical lens 301 to the optical fiber end face 303, and is reflected by the optical fiber end face 303 to the absorption region 102, and the absorption region 102 is also used to absorb the third optical signal reflected by the optical fiber end face 303.

[0083] The light emitting chip can also be fiber coupled with an optical lens and an optical fiber. The optical fiber has an optical fiber end face. Under the action of a fixed test voltage, the light emitting region emits light toward the optical film, and the part of the emitted light first passes through the optical lens, which can be a collimating lens, for example, to transform the dispersed light beam emitted by the light emitting chip into a parallel light beam, and the parallel light beam is coupled into the optical fiber. The optical lens can also be a combination of a collimating lens and a converging lens, the collimating lens first transforms the dispersed light beam emitted by the light emitting chip into a parallel light beam, and the converging lens converges and couples the parallel light beam into the optical fiber. In some embodiments, the optical lens can also be a combination of multiple collimating lenses, converging lenses and other lenses.

[0084] When the light beam emitted by the light emitting region passes through the optical lens to the optical fiber end face, part of the light beam is reflected back by the optical fiber end face as reflected light.

[0085] Because the light emitting chip and the optical lens and the optical fiber are located on the same optical path, the absorption region can absorb the reflected light reflected back by the optical fiber end face.

[0086] The embodiments of the present application also have the following examples, such as Figure 7 as shown in the following figure:

[0087] With the increasingly wide application of semiconductor light devices, the optical performance requirements for semiconductor light emitting chips are also increasingly high. At present, in the process of manufacturing light emitting chips, coating an optical film on the light emitting end face of the chip to improve the optical performance is a common means. Therefore, it is particularly important to monitor the characteristics thereof during the coating process of the optical film. The embodiments of the present application provide a test method for monitoring the characteristics of the optical film by testing the current change of the chip. The test principle is that when the light emitted by the chip passes through the optical film, reflected light is generated, and the reflected light can cause a change in the carrier in the chip, and the reflectivity and other characteristics of the optical film are tested by monitoring the current change caused in the chip. The specific test method is as follows:

[0088] The super radiation light emitting diode chip bar 100 is placed in an end face film coating fixture, and the P face electrode and the N face electrode of the light emitting region 101 of the super radiation light emitting diode chip 100 are respectively bonded with gold wires to lead out two electrodes, and then the lead wires 105 and 106 are connected to the working circuit 201, and in this way, the electrodes of the light emitting regions of multiple chips can be led out to the working circuit at the same time.

[0089] The P face electrode and the N face electrode of the absorption region 102 of the super radiation light emitting diode chip 100 are also respectively bonded with gold wires to lead out two electrodes, and then the lead wires 107 and 108 are connected to the monitoring current test circuit 202, and the monitoring current of one or more super radiation diode dies can be used as the basis for judging the film coating quality.

[0090] The light emitting region 101 is supplied with a certain voltage by the working circuit 201, and the voltage value is fixed. When the light emitted by the super-radiation light emitting diode chip 100 is reflected by the optical film 104, the reflected light returns to the light emitting region 101 and reaches the absorption region 102, causing the change of the carriers, so that the current measured by the current measuring circuit 202 connected with the absorption region 102 changes.

[0091] Because the smaller the reflectivity of the chip end surface film system, the smaller the monitoring current, the quality of the chip end surface anti-reflection film and the change of the film thickness during the film plating process are monitored by testing the change of the monitoring current during the film plating process. The better the quality of the anti-reflection film, the smaller the monitoring current will be, and the worse the quality of the anti-reflection film, the larger the monitoring current will be. When the value of the monitoring current is less than a certain current range, it is considered that the quality of the anti-reflection film at this time is qualified; when the value of the monitoring current is greater than a certain current range, it is considered that the quality of the anti-reflection film at this time is unqualified.

[0092] The present application also has another example as follows, as shown in Figure 8

[0093] Because the reflection of the optical fiber end surface to the light will produce spectral ripple, and the spectral ripple will reduce the precision of the optical device, therefore, it is particularly important to monitor the reflected light on line during the optical fiber coupling process. The present application provides a method for monitoring the reflection during the optical fiber coupling process by measuring the change of the current in the chip caused by the reflected light in the chip.

[0094] The super-radiation light emitting diode chip bar 100 which has been plated with the anti-reflection film is placed in the coupling clamp, and then the P surface electrode and the N surface electrode of the light emitting region 101 of the super-radiation light emitting diode chip 100 are respectively bonded by gold wires to lead out two electrodes, and then the lead wires 105 and 106 are connected to the working circuit 201, and in this way, the electrodes of the light emitting regions of multiple chips can be led out to the working circuit.

[0095] The P surface electrode and the N surface electrode of the absorption region 102 of the super-radiation light emitting diode chip 100 are bonded by gold wires to lead out two electrodes, and then the lead wires 107 and 108 are connected to the monitoring current test circuit 202.

[0096] The light emitting region 101 is supplied with a certain voltage by the working circuit 201, and the voltage value is fixed. When the light emitted by the super-radiation light emitting diode chip 100 is reflected by the optical film 104, the reflected light returns to the light emitting region 101 and reaches the absorption region 102, causing the change of the carriers, so that the current measured by the current measuring circuit 202 connected with the absorption region 102 changes.

[0097] ​In the process of fiber coupling, by adjusting the distance and angle between the chip end face 104, the coupling lens 301 and the optical fiber 302, and other coupling conditions, which factors affect the coupling efficiency can be studied. For example, when the distance between the chip end face 104 and the coupling lens 301 is constantly changed, at a certain position, the monitoring current is found to be the smallest, at this time the spectral ripple is also small, so that the optimal distance of the chip end face and the coupling lens is obtained.

[0098] When the value of the monitoring current is less than a certain current range, it is considered that the distance of the fiber coupling at this time is within the optimal distance range; when the value of the monitoring current is greater than a certain current range, it is considered that the distance of the fiber coupling at this time is not within the optimal distance range.

[0099] The embodiment of the present application also has another example as follows:

[0100] The super-radiation light emitting diode chip bar which has been plated with an anti-reflection film is placed in a coupling clamp, and then the P-surface electrode and the N-surface electrode of the light emitting area of the super-radiation light emitting diode chip are respectively bonded with gold wires to lead out two electrodes and are connected to a working circuit, and so on, so that the electrodes of the light emitting area of multiple chips can be simultaneously led out to the working circuit.

[0101] The P-surface electrode and the N-surface electrode of the absorption area of the super-radiation light emitting diode chip are bonded with gold wires to lead out two electrodes and are connected to a monitoring current test circuit.

[0102] Multiple optical fibers are connected, the light beam emitted by the light emitting area of the super-radiation light emitting diode chip enters the multiple optical fibers, and the reflected light is reflected from the end surface of the multiple optical fibers and enters the absorption area of the light emitting chip, causing a change in the current.

[0103] By observing the monitoring current, the end surface connection quality when the multiple optical fibers are connected is judged, and when the monitoring current is within a target range, the end surface connection quality when the multiple optical fibers are connected at this time meets the requirements.

[0104] It should be understood that the "one embodiment" or "an embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that the size of the sequence number of each process in various embodiments of the present application does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The sequence number of the above embodiments of the present application is only for description, not representing the advantages and disadvantages of the embodiments.

[0105] It should be noted that, as used in this document, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a", "comprising", or "comprises" does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0106] The above descriptions are only the preferred embodiments of the application, not intended to limit the application. Any modification, equivalent, or improvement made within the technical scope of the application should be covered in the scope of the application. The scope of the application should be defined by the claims.

Claims

1. A method of testing a light emitting chip, characterized by, The method comprises: applying a test voltage to a light-emitting region of a light-emitting chip; wherein the light-emitting chip has an optical film on a light-emitting surface thereof, the light-emitting region of the light-emitting chip is configured to emit a first light signal to the optical film under the action of the test voltage; the light-emitting chip further comprises an absorption region, the absorption region is located on the same optical path as the light-emitting region and the optical film, and the absorption region is configured to absorb a second light signal reflected by the optical film; a measurement circuit connected to the absorption region detects a current value of the absorption region, thereby detecting crosstalk light caused by reflection; wherein the current value has a corresponding relationship with the second light signal reflected by the optical film.

2. The method of claim 1, wherein, The light-emitting region of the light-emitting chip comprises an active layer; the active layer comprises at least one section, and different sections of the active layer have different light-emitting wavelengths.

3. The method of claim 1, wherein, The method further comprises: adjusting a film quality parameter of the optical film according to the current value; after adjusting the film quality parameter, the current value is re-detected until the current value meets a first predetermined current range.

4. The method of claim 3, wherein, The film quality parameter of the optical film comprises at least one of: a thickness of the optical film; a reflectivity of the optical film; and a uniformity of the optical film.

5. The method of claim 1, wherein, The light-emitting chip further comprises an optical lens and an optical fiber, the optical fiber has an optical fiber end face; the method further comprises: adjusting a positional relationship between the optical film, the optical lens and the optical fiber end face according to the current value; wherein the first light signal emitted by the light-emitting region passes through the optical lens to reach the optical fiber end face, and is reflected to the absorption region at the optical fiber end face, and the absorption region is further configured to absorb a third light signal reflected by the optical fiber end face; after adjusting the positional relationship, the current value is re-detected until the current value meets a second predetermined current range.

6. The method of claim 5, wherein, The adjusting of the positional relationship between the optical film, the optical lens and the optical fiber end face according to the current value comprises: adjusting the positional relationship between the optical lens and the optical fiber end face according to the current value; wherein the optical film and the optical lens have a fixed positional relationship.

7. The method of claim 5, wherein, The adjusting of the positional relationship between the optical film, the optical lens and the optical fiber end face according to the current value comprises: adjusting the positional relationship between the optical lens and the optical film according to the current value; wherein the optical film and the optical fiber end face have a fixed positional relationship.

8. The method according to any one of claims 5 to 7, characterized in that, The positional relationship comprises: a distance relationship; and / or an angle relationship.

9. A light emitting chip, characterized by Comprise: a light-emitting region, the light-emitting region has an optical film on a light-emitting surface thereof, and the light-emitting region is configured to emit a first light signal to the optical film when a test voltage is applied thereto; an absorption region, located on the same optical path as the light-emitting region and the optical film, configured to absorb a second light signal reflected by the optical film, and the absorption region is configured such that, when it is connected to a measurement circuit, the measurement circuit can detect a current value of the absorption region, thereby detecting crosstalk light caused by reflection.

10. The light emitting die of claim 9, wherein, The light-emitting chip further comprises: An optical lens and an optical fiber located in the same optical path as the optical film; the optical fiber further comprises an optical fiber end face; wherein the first light signal emitted by the light emitting area reaches the optical fiber end face through the optical lens, and is reflected to the absorption area at the optical fiber end face, and the absorption area is further used for absorbing the third light signal reflected by the optical fiber end face.

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