TWI722379B - Transparent conducting film or coating on a lens that serves as an interlock on a semiconductor laser module - Google Patents

Abstract

Method and apparatuses are described herein for providing laser safety in semiconductor laser modules. For example, a semiconductor laser module may comprise a semiconductor laser and an optical element. The optical element that is operatively coupled with the semiconductor laser may disperse the laser light emitted from the semiconductor laser. The optical element may be coated with a transparent conductive material that serves as an interlock on the semiconductor laser. The transparent conductive material may be placed in the shape of a trace on the optical element where the trace is electrically in series with the semiconductor laser. On a condition that the trace is damaged, the laser light emitted from the semiconductor laser may be interrupted.

Description

As a transparent conductive film or coating on the interlocking lens of the semiconductor laser module

The disclosed embodiment generally relates to a semiconductor laser module, and more specifically relates to the safety of a semiconductor laser using a transparent conductive film or coating on an interlocking lens.

Semiconductor lasers such as vertical cavity surface emitting lasers (VCSEL) are widely used for facial or iris recognition. Specifically, the laser radiation is dispersed into a large solid angle by a transparent optical element or lens, and then directed toward the iris or face. The camera module can detect the reflected radiation, and then the image processing algorithm can perform biometric identification. In order for these laser modules to be considered safe, they need to comply with laser safety standards, such as the International Electrotechnical Commission (IEC) 60825. In the conventional laser module, a metal sheet (or metal cap) is used to provide laser safety and meet these safety standards. For example, if the metal sheet is damaged, removed or broken, the electrical connection with the laser is interrupted and the laser is turned off. However, these conventional laser modules are bulky and incomplete because they require a separate metal sheet to detect damage in the laser module. In addition, the metal sheet needs to contain a hole through which the laser light is emitted. If damage occurs on the part of the lens exposed through the hole, the conventional laser module cannot turn off the laser light because this part is not protected by the metal sheet. Therefore, it is desirable to have an interlocking The transparent conductive film or coating on the lens provides a method and equipment for complete laser safety with reduced size.

This article describes methods and equipment used to provide laser safety in semiconductor laser modules. For example, a semiconductor laser module may include a semiconductor laser and a transparent optical element. The semiconductor laser can emit laser light through the transparent optical element. The transparent optical element operatively coupled and positioned to receive the emitted laser light from the semiconductor laser can diffuse the emitted light at an increased solid angle, thereby effectively dispersing or diffusing from the semiconductor laser Shoot the laser light emitted. Since the optical element is transparent, scattering is kept to a minimum and most of the emitted light is kept within a predefined solid angle larger than the originally emitted laser light. The optical element may be coated with a transparent conductive material that acts as an interlock on the semiconductor laser by providing a part of the serial connection with the semiconductor laser. In addition, the transparent conductive material can be placed on the optical element in the shape of a trace, wherein the trace is connected in series with the semiconductor laser. Under the condition that the trace is damaged, cracked or broken, the laser light emitted from the semiconductor laser can be interrupted. The transparent conductive material may include at least one of indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), or indium-doped zinc oxide (IZO).

100: Semiconductor laser module

110: Semiconductor laser

120: optical components

130: Transparent conductive layer

140: Printed Circuit Board (PCB)

220: optical components

230: trace

232: Endpoint

234: Endpoint

240: optical components

250: trace

252: Endpoint

254: Endpoint

310: ITO trace

320: current

330: ITO trace

340: Vertical cavity surface emitting laser (VCSEL)

350: Laser light

410: ITO trace

420: Current

430: ITO trace

440: Vertical cavity surface launch laser (VCSEL)

450: Laser light

460: Field Effect Transistor (FET)

470: resistor

510: Step

530: step

A more detailed understanding can be obtained from the following description given in conjunction with the examples of the drawings, in which the same component symbols in the drawings represent the same components, and among them: FIG. 1A shows a system diagram of an example semiconductor laser module, The semiconductor laser module includes a transparent optical element coated with a transparent conductive material as an interlock; FIG. 1B is a three-dimensional view of the example semiconductor laser module shown in FIG. 1A; FIG. 2A is a diagram showing an example shape of a trace that can be used in the semiconductor laser module shown in FIG. 1A and FIG. 1B; FIG. 2B is a diagram that can be shown in FIG. 1A and FIG. 1B A diagram of another example shape of the trace used in the semiconductor laser module; Figure 3A shows one of a current flowing through a vertical cavity surface emitting laser (VCSEL) when an ITO trace is not damaged A diagram of an example connection; FIG. 3B shows a diagram of an example connection when an ITO trace is damaged and a current is interrupted; FIG. 4A shows a diagram of an ITO trace in the gate of a field-effect transistor (FET) A diagram of an example connection when a current flows through a VCSEL when the wire is not damaged; FIG. 4B is a diagram showing an example connection when an ITO trace in the gate is damaged to a FET when a current is interrupted; FIG. 5 It is a diagram showing an example of the manufacturing process for providing laser safety using an optical element coated with a transparent conductive material.

It should be understood that the diagrams and descriptions of the method and equipment used as a transparent conductive film or coating on an interlocking lens of a semiconductor laser module have been simplified for the sake of clear understanding to illustrate the related Components, while eliminating many other components found in typical device processing for clarity purposes. Those skilled in the art can recognize other elements and/or steps that are desired and/or required when implementing the present invention. However, because these elements and steps are well known in the art, and because they do not promote a better understanding of the present invention, a discussion of these elements and steps is not provided herein.

This article describes a method and device for a semiconductor laser module, which The semiconductor laser module has a transparent conductive film or coating on an optical element (or lens) as an interlock. For example, a semiconductor laser module may include a semiconductor laser and a transparent optical element (or a lens). The transparent optical element that is operatively coupled and positioned to receive the emitted laser light from the semiconductor laser can diffuse the emitted light at an increased solid angle, thereby effectively dispersing or diffusing the emitted light from the semiconductor laser. The laser light emitted by a semiconductor laser. Since the optical element is transparent, scattering is kept to a minimum and most of the emitted light is kept within a predefined solid angle larger than the originally emitted laser light. The optical element may be coated with a transparent conductive material that acts as an interlock on the semiconductor laser by providing a part connected in series with one of the semiconductor lasers. The transparent conductive film or coating may be in the shape of a trace, wherein the trace is connected in series with the semiconductor laser. If the trace is damaged, broken or broken by an external force, the laser light emitted from the semiconductor laser can be turned off. The transparent conductive film or coating can be made of, for example, indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), or any combination thereof to make.

FIG. 1A shows an example semiconductor laser module 100 which includes an optical element 120 formed or coated with a transparent conductive layer 130. The transparent conductive layer 130 can be used as an interlock on a semiconductor laser 110. For example, the semiconductor laser module 100 includes a semiconductor laser 110, a transparent optical element 120, a transparent conductive layer 130, and a printed circuit board (PCB) 140.

The semiconductor laser 110 is a device that causes the laser to oscillate by flowing a current to the semiconductor. Specifically, light is generated by flowing forward current to the p-n junction. In the forward bias operation, the p-type layer is connected to the positive terminal, the n-type layer is connected to the negative terminal, electrons enter from the n-type layer, and holes enter from the p-type layer. When the two meet at the junction, an electron falls into an electric hole and emits light at this time. Types of semiconductor laser 110 include (but are not limited to) laser diode (LD), double heterostructure laser (DH), separation limited heterostructure laser (SCH), distributed cloth Lager reflector laser (DBR), distributed feedback laser (DFB), quantum well laser, quantum dot laser, quantum cascade laser (QCL), external cavity laser (ECL), extended cavity diode Volume lasers, Bragg gate lasers, vertical cavity surface emitting lasers (VCSEL), vertical external cavity surface emitting lasers (VECSEL), hybrid silicon lasers, interband cascade lasers (ICL) and semiconductors Ring laser. As used herein, the terms semiconductor laser, laser diode (LD), injection laser diode (ILD) or diode laser and variants thereof are used interchangeably in this disclosure.

In an embodiment, the semiconductor laser 110 may be an infrared red laser, such as a vertical cavity surface emitting laser (VCSEL). VCSEL can be used for facial and iris recognition. When implementing a VCSEL in an application such as iris or facial recognition, the semiconductor laser module 100 needs to comply with laser safety regulations, such as the International Electrotechnical Commission (IEC) 60825. This may require a feature in the semiconductor laser module 100, which turns off the laser when the system becomes unsafe. For example, this happens when the optical element 120 (or lens) in a semiconductor laser module 100 is broken, removed or broken.

The optical element 120 is a transparent lens, ridge or other element, which diffuses or disperses the laser radiation with a large solid angle with minimal scattering, making it safe to use. Without the optical element 120 (or lens), the system will be unsafe to use. This is especially worrying when the system is used for iris recognition in a mobile application. The optical element 120 can be any type of optical lens. Examples of the optical element 120 include, but are not limited to, a convex lens, a biconvex lens, an isometric lens, a concave lens, a biconcave lens, a plano-convex lens, a plano-concave lens, a convex-concave (or meniscus) lens, and a positive meniscus lens , A negative meniscus lens and a positive (or converging) lens. Although the optical element 120 is shown as a rectangular shape in FIGS. 1A and 1B, the optical element 120 is not limited to this shape and can be any type of two-dimensional or three-dimensional shape. For example, the optical element 120 may be circular, elliptical, oval, square, rectangular, triangular, five-sided Shape, hexagon, octagon, triangle, cylinder, sphere, disc, cube, cone, pyramid, triangular prism, pentagonal prism, hexagonal prism, or the like.

As shown in FIG. 1A, the optical element 120 may be formed into a film or coated with a transparent conductive layer 130, and the transparent conductive layer 130 is used as an interlock for laser safety. In particular, the transparent conductive layer 130 may be shaped as a trace electrically connected in series with the semiconductor laser 110. When the optical element 120 (or lens) is damaged, cracked or broken, the transparent conductive layer 130 (ie, the trace) is electrically interrupted, which causes the semiconductor laser 110 to stop working. This can prevent the semiconductor module 100 from becoming unsafe.

The transparent conductive layer 130 can be made of any optically transparent conductive material. Examples of these transparent conductive materials include (but are not limited to) indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), Indium-doped cadmium oxide (CdO: In), carbon nanotubes, graphene, intrinsically conductive polymers (ICP), amorphous indium zinc oxide and silver nanoparticles-ITO hybrids.

The semiconductor laser 110 and the transparent conductive layer 130 (ie, the trace) are electrically connected in series with the printed circuit board (PCB) 140, and a current is provided therein. When the semiconductor laser module 100 is operating normally (ie, the trace is not damaged), the current can circulate the semiconductor laser 110, the transparent conductive layer 130, and the PCB 140. FIG. 1B is a three-dimensional view of the semiconductor laser module 100 shown in FIG. 1A.

2A and 2B show example shapes of traces 230, 250 on optical elements 220, 240, which can be used in combination with any of the embodiments described herein. As shown in FIG. 2A, the trace 230 may have a curved (or heat sink) shape. As shown in FIG. 2B, the trace 240 may have a spiral shape. The traces 230, 250 can have any type of shape. Example shapes of the traces 230, 250 include, but are not limited to, a curved shape, a coiled shape, a striped shape, a box shape, a circular shape, a spiral shape, and a triangular shape. The traces 230 and 250 may partially or completely cover the surface of the optical elements 220 and 240. However, traces 230, 250 may need to be dense The ground is placed on the surface of the optical elements 220, 240 to the extent that if an event occurs, they can detect any damage on the optical elements 220, 240. For example, if the optical element 220, 240 cracks or breaks, the current on the traces 230, 250 is interrupted. Since the semiconductor laser is electrically connected to the PCB and the traces 230, 250, when the traces 230, 250 on the optical components 220, 240 are damaged, the semiconductor laser can be turned off. The terminals 232, 234, 252, and 254 of the traces 230, 250 can be connected to the PCB. Current can flow into the terminals 232 and 252 and flow out through the terminals 234 and 254, and vice versa.

FIG. 3A shows an example connection of a current 320 flowing through a vertical cavity surface emitting laser (VCSEL) 340 when the ITO trace 310 is not damaged. Although the trace 310 may not include a switch thereon, the operation of the VCSEL 340 as an example can be illustrated by representing a switch of the ITO trace 330. For example, when there is no damage on the ITO trace 310, the current 320 flows through the VCSEL 340 as if the switch controlling the VCSEL (ie, the switch representing the ITO trace 330) is connected or closed. When the switch representing the ITO trace 330 is connected or closed (ie, there is no damage on the ITO trace 310), the current 320 flows into the VCSEL 340, and thereby the VCSEL 340 can emit the laser light 350. It should be noted that VCSEL 340 can be replaced with any type of semiconductor laser, such as laser diode (LD), double heterostructure laser (DH), separation confinement heterostructure laser (SCH), distributed Bragg reflector laser (DBR), Distributed Feedback Laser (DFB), Quantum Well Laser, Quantum Dot Laser, Quantum Cascade Laser (QCL), External Cavity Laser (ECL), Extended Cavity Diode Laser, Volume Bragg Gate laser, vertical external cavity surface emitting laser (VECSEL), hybrid silicon laser, interband cascade laser (ICL), semiconductor ring laser or the like.

FIG. 3B shows an example connection when a current 320 is interrupted when an ITO trace 310 is damaged. Similar to FIG. 3A, although the trace 310 may not include a switch thereon, as an example, the operation of the VCSEL 340 can be illustrated by representing a switch of the ITO trace 330. E.g, When the ITO trace 310 is broken, broken or broken, the current 320 may not flow through the VCSEL 340, as if the switch controlling the VCSEL (ie, the switch representing the ITO trace 330) is disconnected or disconnected. When the switch representing the ITO trace 330 is disconnected or disconnected (ie, there is damage on the ITO trace 310), the VCSEL 340 turns off the laser light 350, thereby preventing unsafe conditions.

FIG. 4A shows an example connection of a current 420 flowing through a VCSEL 440 when one of the ITO traces 410 in the gate of a field effect transistor (FET) 460 is not damaged. Although the trace 410 may not include a switch thereon, the operation of the VCSEL 440 as an example can be illustrated by representing a switch of the ITO trace 430. For example, when there is no damage on the ITO trace 410, the current 420 flows into the VCSEL 440 and the FET, as if the switch controlling the VCSEL (that is, the switch representing the ITO trace 430) is connected or closed.

In the case where the ITO trace 410 may not conduct the current 420 well, the FET 460 and the resistor 470 can be used to amplify the current 420. The FET 460 can be positioned anywhere in the VCSEL module, such as a PCB. However, it needs to be connected to the trace 410 to ensure that the current 420 flows through the VCSEL 440. Although not shown in FIG. 4A, any type of transistor or switch can be used for the FET 460.

Similar to FIG. 3A, when the switch representing the ITO trace 430 is connected (ie, there is no damage on the ITO trace 410), the current 420 flows into the VCSEL 440 and the FET 460, and thereby the VCSEL 440 emits laser light 450. It should be noted that VCSEL 440 can be replaced by any type of semiconductor laser, such as laser diode (LD), double heterostructure laser (DH), separation confinement heterostructure laser (SCH), distributed Bragg reflector laser (DBR), Distributed Feedback Laser (DFB), Quantum Well Laser, Quantum Dot Laser, Quantum Cascade Laser (QCL), External Cavity Laser (ECL), Extended Cavity Diode Laser, Volume Bragg grating laser, vertical external cavity surface emitting laser (VECSEL), hybrid silicon laser, interband cascade laser (ICL), semiconductor ring laser or Similar.

FIG. 4B shows an example connection in which a current 420 is interrupted when one of the ITO traces 410 in the gate of a FET 460 is damaged. Similar to FIG. 4A, although the trace 410 may not include a switch thereon, the operation of the VCSEL 440 as an example can be illustrated by representing a switch of the ITO trace 430. For example, when the ITO trace 410 is damaged, broken or broken, the current 420 cannot flow through the VCSEL 440 and the FET 460, as if controlling the switch of the VCSEL 440 (ie, the switch representing the ITO trace 430) to disconnect or disconnect. When the switch representing the ITO trace 430 is disconnected or disconnected (ie, there is damage on the ITO trace 410), the VCSEL 440 turns off the laser light 450, thereby preventing unsafe conditions.

Figure 5 shows an example program for using an optical element to provide laser safety, the optical element is formed or coated with a transparent conductive material, the transparent conductive material as an interlock on a semiconductor laser module . This example program can be used in combination with any of the embodiments described herein. For example, at step 510, a semiconductor laser in a semiconductor laser module emits laser light through an optical element or lens. The optical element coupled with the semiconductor laser can disperse or diffuse the laser light emitted from the semiconductor laser. The optical element can be formed into a film or coated with a transparent conductive material, which acts as an interlock on the semiconductor laser. Examples of the transparent conductive material include indium tin oxide (ITO), aluminum doped zinc oxide (AZO), gallium doped zinc oxide (GZO), indium doped zinc oxide (IZO), indium doped cadmium oxide (CdO: In), carbon nanotubes, graphene, intrinsically conductive polymers (ICP), amorphous indium zinc oxide, silver nanoparticles-ITO hybrid, or any combination thereof.

The transparent conductive material can be placed in any shape that can detect damage on the optical element. For example, it can be in the shape of a trace. Examples of the shape of the transparent conductive material include a curved shape, a heat sink shape, a spiral shape, a circular shape, a polygonal shape, A triangular shape, a square shape, a rectangular shape, a trapezoidal shape or the like. The trace can be connected in series with the semiconductor laser so that the current flows from a PCB to the semiconductor laser. In the event that the trace is damaged, cracked or broken, the trace is electrically interrupted, which causes the semiconductor laser to stop operating or shut down at step 530.

The embodiments described herein can be incorporated into any suitable transparent conductive film or coating on a lens that interlocks as one of the semiconductor laser modules. The embodiments of the present invention are not limited to the specific structure shown. It should be noted that the shape of the trace on an optical element described above is only one example or case of many other possibilities.

The non-limiting method and equipment described herein for a transparent conductive film or coating on an interlocking lens of a semiconductor laser module can be modified for various applications and uses. At the same time, stay within the spirit and scope of the patent application. The implementations and modifications described herein and/or shown in the drawings are presented as examples only, and are not limited in scope and spirit. The description in this article can be applied to all implementations of methods and equipment used as a transparent conductive film or coating on an interlocking lens on a semiconductor laser module, but it can be related to a specific implementation. Describe.

As described herein, the methods described herein are not limited to any specific elements that perform any specific functions, and some steps of the presented methods do not necessarily occur in the order shown. For example, in some cases, two or more method steps may occur in a different order or simultaneously. In addition, some steps of the described method may be optional (even if not explicitly stated as optional), and therefore may be omitted. These and other variations of the methods disclosed herein will be obvious, especially in view of the description of one of the methods and devices described herein, and are considered to be within the full scope of the present invention.

Some features of some embodiments can be omitted and implemented together with other embodiments Shi. The device elements and method elements described herein are interchangeable, and can be used in or omitted from any examples or implementations described herein.

Although the features and elements are described above in specific combinations, each feature or element can be used alone without other features and elements, or in various combinations with or without other features and elements.

100‧‧‧Semiconductor laser module

110‧‧‧Semiconductor laser

120‧‧‧Optical components

130‧‧‧Transparent conductive layer

140‧‧‧Printed Circuit Board (PCB)

Claims (17)

A semiconductor laser module includes: a semiconductor laser; and an optical element operatively coupled with the semiconductor laser to disperse the laser light emitted from the semiconductor laser, wherein the optical element is coated Covered with a transparent conductive material in the form of a trace as an interlock on the semiconductor laser, and the trace covers at least a substantial portion of the optical element relative to a surface of the semiconductor laser section. The semiconductor laser module of claim 1, wherein the transparent conductive material includes indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), or indium-doped zinc oxide (IZO) at least one. Such as the semiconductor laser module of claim 1, wherein the trace is connected in series with the semiconductor laser. The semiconductor laser module of claim 1, wherein the laser light emitted from the semiconductor laser is interrupted under one of the conditions that the trace is damaged. The semiconductor laser module of claim 1, wherein the transparent conductive material covers most of the at least one sidewall of the optical element adjacent to the surface of the semiconductor laser. The semiconductor laser module of claim 5, wherein: the connection to the trace extends to opposite sidewalls, and the transparent conductive material covers the optical element adjacent to the surface of the optical element with respect to the semiconductor laser Opposite most of the side wall. The semiconductor laser module of claim 1, wherein the trace is formed as a radiator shape that extends across almost all portions of the optical element relative to the surface of the semiconductor laser. The semiconductor laser module of claim 7, wherein the connection to the trace is located on the opposite side of the same side wall of the optical element adjacent to the surface of the semiconductor laser. The semiconductor laser module of claim 1, wherein the trace is formed as a spiral shape extending across almost all parts of the surface of the optical element with respect to the semiconductor laser. The semiconductor laser module of claim 9, wherein the same side of the same side wall of the optical element connected to the optical element adjacent to the surface of the semiconductor laser adjoins each other to the trace. The semiconductor laser module of claim 1, wherein the trace completely covers the surface of the optical element relative to the semiconductor laser. The semiconductor laser module of claim 1, wherein the trace directly supplies a current to an anode or a cathode of the semiconductor laser. The semiconductor laser module of claim 1, wherein the trace provides a current to a gate of a transistor connected in series with the semiconductor laser, and the transistor is used to control the current passing through the semiconductor laser. A method of interrupting laser light, comprising: emitting laser light from a semiconductor laser; dispersing the laser light emitted from the semiconductor laser at an optical element operatively coupled with the semiconductor laser; and in the optical element The laser light is interrupted under a condition of damage, wherein the optical element is coated with a transparent conductive material in the form of a trace, and the trace covers at least a substantial part of a surface of the optical element with respect to the semiconductor laser and serves as One of the semiconductor lasers is interlocked. The method of claim 14, wherein the transparent conductive material comprises indium tin oxide (ITO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), or indium-doped zinc oxide (IZO) At least one. The method of claim 14, wherein the trace is connected in series with the semiconductor laser. The method of claim 14, wherein the laser light emitted from the semiconductor laser is interrupted under a condition of the trace damage.

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