Miniature body-absorbing light trap for laser communication systems

Abstract

A kind of laser communication system micro body absorbs light trap, and the light trap is vitreous body, and the whole is cuboid structure;The upper end surface and the lower end surface of light trap are all right trapezoidal, and the remaining four side faces are all rectangular plane;The side face corresponding to the oblique waist side edge of the upper end surface in light trap is defined as the first working surface, the side face corresponding to the lower bottom edge of the upper end surface is defined as the second working surface, the side face corresponding to the right angle waist side edge of the upper end surface is defined as the third working surface, and the side face corresponding to the upper bottom edge of the upper end surface is defined as the fourth working surface;Stray light beam is vertically incident from the first working surface to the inside of light trap, and total reflection occurs on the second working surface, the third working surface and the fourth working surface;The vitreous body for manufacturing light trap is light-absorbing glass material, and stray light beam is continuously absorbed by glass body in the process of multiple total reflections, so as to realize stray light suppression.

Description

Technical Field

[0001] This invention relates to a miniature absorption light trap for a laser communication system, belonging to the field of integrated laser communication. Background Technology

[0002] Modularization and miniaturization are inevitable trends for future space-based laser networking in high-speed laser communication. Currently, laser communication terminals with common aperture and common optical path transceiver typically have the advantages of small size and lightweight design, while also possessing high-power laser emission and high-sensitivity signal light reception capabilities. However, the emitted laser power of a laser communication terminal is usually much higher than the received signal power. Therefore, in a common optical path transceiver system, stray light formed by reflection and scattering of the emitted laser after passing through planar optical elements and structural walls can easily overwhelm the weak received signal light, leading to communication failure.

[0003] To prevent the received weak signal light from being annihilated by stray light generated by the transmitted signal light of the same wavelength, stray light removal processing is required to isolate the transmitted and received signal light. Common methods for removing stray light include surface treatments such as blackening with paint or anodizing the structural wall. However, these methods have weak stray light suppression capabilities, with a stray light suppression ratio (the ratio of untreated stray light energy to total stray light energy) of only about -13dB. Absorbing stray light before it reaches the diffuse reflection of the structural wall is also an effective way to eliminate stray light. This method is accomplished by setting up optical traps. However, existing optical traps mostly utilize multiple reflections by curved mirrors with specific curvatures in the cavity to absorb and eliminate stray light. Most of these are bulky, structurally complex, and difficult and costly to manufacture. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of existing technologies and provide a miniature light-absorbing trap for laser communication systems. This light trap achieves total internal reflection through a specific shape, maximizing the optical path while ensuring a small volume, thereby ensuring sufficient absorption of light energy and improving stray light suppression capability. This solves the problems of existing light traps being bulky, complex in structure, and weak in stray light suppression capability.

[0005] The technical solution of this invention is: A miniature light-absorbing trap for a laser communication system is characterized in that: the light trap is a glass body with an overall rectangular parallelepiped structure; the upper and lower surfaces of the light trap are both right-angled trapezoids, and the remaining four sides are rectangular planes; The side surface formed between the inclined waist side of the upper end face and the inclined waist side of the lower end face in the light trap is defined as the first working surface D1, the side surface formed between the lower bottom edge of the upper end face and the lower bottom edge of the lower end face is defined as the second working surface D2, the side surface formed between the right-angle waist side of the upper end face and the right-angle waist side of the lower end face is defined as the third working surface D3, and the side surface formed between the upper top edge of the upper end face and the lower top edge of the lower end face is defined as the fourth working surface D4. The stray light beam is incident perpendicularly into the light trap from the center of the first working surface D1, and undergoes total internal reflection in sequence on the second working surface D2, the third working surface D3 and the fourth working surface D4. The glass body that manufactures the light trap is made of light-absorbing glass. During the total internal reflection, the stray light beam is continuously absorbed by the glass body, thereby achieving stray light suppression.

[0006] Furthermore, the first working surface D1 is coated with an anti-reflective film, and the second working surface D2, the third working surface D3, and the fourth working surface D4 are all polished.

[0007] Furthermore, the included angle between the first working surface D1 and the second working surface D2 of the light trap satisfy ;in, n The refractive index of the glass used to create light traps.

[0008] Furthermore, the ratio of the upper base to the height of the upper surface in a light trap is defined as the shape ratio. Shape than satisfy ;in, The angle between the first working surface D1 and the second working surface D2 of the light trap. It is the distance from the incident point of the stray light beam on the first working surface D1 to the common edge of the first working surface D1 and the second working surface D2.

[0009] Furthermore, during the propagation of the stray light beam inside the optical trap, it first intersects with the second working surface D2 and undergoes a first total internal reflection; then, the stray light beam is reflected to the third working surface D3 and undergoes a second total internal reflection; then, the stray light beam is reflected to the third working surface D3 and undergoes a third total internal reflection; finally, the stray light beam exits the optical trap from the first working surface D1.

[0010] Furthermore, the distance the stray light beam travels from its incident point into the optical trap until the first total internal reflection occurs. for

[0011] The distance the stray light beam travels from the first total internal reflection to the second total internal reflection. for

[0012] in, The length of the bottom edge of the upper surface of the light trap; The distance the stray light beam travels from the second total internal reflection to the third total internal reflection. for

[0013] in, The height of the upper surface of the light trap; The distance the stray light beam travels from the third total internal reflection to the point of exiting the light trap. for

[0014] in, The length of the top base of the light trap's upper surface.

[0015] Furthermore, the stray light suppression ratio of the light trap is... for

[0016] in, L The optical path length of the stray light beam as it propagates within the optical trap. ; The absorption coefficient of the vitreous body used to create the light trap.

[0017] Secondly, the present invention also proposes a laser communication system, comprising: an optical signal transmitting module, an optical signal receiving module, and a stray light suppression module; the stray light suppression module employs a miniature absorption light trap as described above in a laser communication system. The optical signal transmitting module is used to transmit optical signals; the stray light suppression module is used to suppress stray light in the optical signal; and the optical signal receiving module is used to receive the optical signal after stray light suppression.

[0018] The advantages of this invention compared to the prior art are: (1) The present invention achieves total internal reflection of light by using a specific shape, thereby maximizing the optical path while ensuring that the light trap has a small volume, thus ensuring that the light trap absorbs sufficient light energy and improving the ability to suppress stray light.

[0019] (2) The light trap designed in this invention is only a cuboid structure, which is easy to process and assemble, and is conducive to widespread use. Attached Figure Description

[0020] Figure 1 This is a top view of a miniature light-absorbing trap in a laser communication system according to the present invention; Figure 2 This is a side view of a miniature light-absorbing trap in a laser communication system according to the present invention; Figure 3 This is a light path diagram of a miniature absorption light trap in a laser communication system according to the present invention; Figure 4 This is a light path diagram of a miniature absorption light trap in a laser communication system according to the present invention, under different aspect ratios. Detailed Implementation

[0021] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0022] like Figure 1 and Figure 2 As shown, the present invention provides a miniature light-absorbing trap for a laser communication system. The light trap is a glass body with an overall rectangular parallelepiped structure. The upper and lower surfaces of the light trap are both right-angled trapezoids, and the remaining four sides are rectangular planes. The side surface corresponding to the inclined waist side of the upper end face in the light trap is defined as the first working surface D1, the side surface corresponding to the bottom edge of the upper end face is defined as the second working surface D2, the side surface corresponding to the right-angle waist side of the upper end face is defined as the third working surface D3, and the side surface corresponding to the top and bottom edges of the upper end face is defined as the fourth working surface D4. The stray light beam is incident perpendicularly into the light trap from the first working surface D1, and undergoes total internal reflection on the second working surface D2, the third working surface D3, and the fourth working surface D4. The glass body that manufactures the light trap is made of light-absorbing glass. During the multiple total internal reflections, the stray light beam is continuously absorbed by the glass body, thereby achieving stray light suppression.

[0023] Furthermore, the first working surface D1 is coated with an anti-reflective film, and the second working surface D2, the third working surface D3, and the fourth working surface D4 are all polished.

[0024] Furthermore, the included angle between the first working surface D1 and the second working surface D2 of the light trap satisfy ;in, n The refractive index of the glass used to create light traps.

[0025] Furthermore, the ratio of the upper base to the height of the upper surface in a light trap is defined as the shape ratio. Shape than satisfy ;in, The angle between the first working surface D1 and the second working surface D2 of the light trap. It is the distance from the incident point of the stray light beam on the first working surface D1 to the common edge of the first working surface D1 and the second working surface D2.

[0026] Furthermore, during the propagation of the stray light beam inside the optical trap, it first intersects with the second working surface D2 and undergoes a first total internal reflection; then, the stray light beam is reflected to the third working surface D3 and undergoes a second total internal reflection; then, the stray light beam is reflected to the third working surface D3 and undergoes a third total internal reflection; finally, the stray light beam exits the optical trap from the first working surface D1.

[0027] like Figure 3As shown, the stray light beam intersects the second working surface D2 at point B, and the angle between the stray beam and the normal to the second working surface D2 is... The light beam is incident from an optically denser medium (glass) to an optically less dense medium (air), and The total internal reflection condition is satisfied; the stray beam is reflected to the third working surface D3 and intersects at point C, with the angle between C and the normal to the third working surface D3 being... The light beam is incident from an optically denser medium (glass) to an optically less dense medium (air), with an angle of incidence of [missing information]. The total internal reflection condition is satisfied; the stray beam is reflected to the fourth working surface D4 and intersects at point D, with the angle between the reflected beam and the normal to the fourth working surface D4 being... The light beam is incident from an optically denser medium (glass) to an optically less dense medium (air), and It satisfies the condition for total internal reflection.

[0028] Furthermore, the distance the stray light beam travels from its incident point into the optical trap until the first total internal reflection occurs. for

[0029] The distance the stray light beam travels from the first total internal reflection to the second total internal reflection. for

[0030] in, The length of the bottom edge of the upper surface of the light trap; The distance the stray light beam travels from the second total internal reflection to the third total internal reflection. for

[0031] in, The height of the upper surface of the light trap; The distance the stray light beam travels from the third total internal reflection to the point of exiting the light trap. for

[0032] in, The length of the top base of the light trap's upper surface.

[0033] Furthermore, the stray light suppression ratio of the light trap is... for

[0034] in, L The optical path length of the stray light beam as it propagates within the optical trap. ; The absorption coefficient of the vitreous body used to create the light trap.

[0035] like Figure 4 As shown, the shape of the light trap is larger than satisfy At that time, that is, the third working face D3 is located Figure 4 When the optical trap is between position 1 and position 2, it is the optimal optical trap, which satisfies both a small size and maximizes the optical path length of the beam within the trap; when At that time, the stray light beam undergoes only two total internal reflections at the third working surface D3 and the fourth working surface D4, resulting in a short optical path; when At this time, although the stray light beam can undergo multiple total internal reflections on the second working surface D2, the third working surface D3, and the fourth working surface D4, the light trap volume is too large to meet practical applications.

[0036] In summary, this invention achieves total internal reflection of light through a specific shape, maximizing the optical path while ensuring the optical trap has a small volume, thereby ensuring sufficient absorption of light energy by the optical trap and improving the ability to suppress stray light. In addition, the optical trap designed in this invention is only a cuboid structure, which is easy to process and assemble, and is conducive to widespread use.

[0037] Secondly, the present invention also proposes a laser communication system, comprising: an optical signal transmitting module, an optical signal receiving module, and a stray light suppression module; the stray light suppression module employs a miniature absorption light trap as described above in a laser communication system. The optical signal transmitting module is used to transmit optical signals; the stray light suppression module is used to suppress stray light in the optical signal; and the optical signal receiving module is used to receive the optical signal after stray light suppression.

[0038] Example: A miniature bulk absorption optical trap suitable for 1550nm wavelength laser communication systems The light trap is a glass body with an overall rectangular parallelepiped structure; the upper and lower surfaces of the light trap are both right trapezoids, and the remaining four sides are rectangular planes. The side surface corresponding to the inclined waist side of the upper end face in the light trap is defined as the first working surface D1, the side surface corresponding to the bottom edge of the upper end face is defined as the second working surface D2, the side surface corresponding to the right-angle waist side of the upper end face is defined as the third working surface D3, and the side surface corresponding to the top and bottom edges of the upper end face is defined as the fourth working surface D4. A stray beam of light is incident perpendicularly into the optical trap from the first working surface D1, and undergoes total internal reflection at the second working surface D2, the third working surface D3, and the fourth working surface D4. The glass body used to manufacture the optical trap is made of germanium, which exhibits good absorption characteristics in the range of 200 nm to 1700 nm, with an absorption coefficient of [value missing] at 1550 nm. The refractive index is taken as The stray light beam is continuously absorbed by the glass during its multiple total internal reflections, thereby achieving stray light suppression. The angle between the first working surface D1 and the second working surface D2 of the light trap It is 56°; satisfying the requirements. That is, satisfying ; The upper surface of the light trap has a top and bottom length of 7mm and a height of 4mm, and its shape is larger than... At this time, the optical path length of the stray light beam within the optical trap is... stray light suppression ratio of light traps .

[0039] The parts of this invention not described in detail are common knowledge to those skilled in the art.

Claims

1. A miniature volumetric light-absorbing trap for a laser communication system, characterized in that: The light trap is a glass body with an overall rectangular parallelepiped structure; the upper and lower faces of the light trap are parallel to each other and are both right trapezoids; the four sides of the light trap are rectangular planes and are all perpendicular to the upper and lower faces. The side surface formed between the inclined waist side of the upper end face and the inclined waist side of the lower end face in the light trap is defined as the first working surface D1, the side surface formed between the lower bottom edge of the upper end face and the lower bottom edge of the lower end face is defined as the second working surface D2, the side surface formed between the right-angle waist side of the upper end face and the right-angle waist side of the lower end face is defined as the third working surface D3, and the side surface formed between the upper top edge of the upper end face and the lower top edge of the lower end face is defined as the fourth working surface D4. The stray light beam is incident perpendicularly into the light trap from the center of the first working surface D1, and undergoes total internal reflection in sequence on the second working surface D2, the third working surface D3 and the fourth working surface D4. The glass body that manufactures the light trap is made of light-absorbing glass. During the total internal reflection, the stray light beam is continuously absorbed by the glass body, thereby achieving stray light suppression.

2. The miniature absorption light trap for a laser communication system according to claim 1, characterized in that: The first working surface D1 is coated with an anti-reflective film, and the second working surface D2, the third working surface D3 and the fourth working surface D4 are all polished.

3. The miniature absorption light trap for a laser communication system according to claim 1, characterized in that: The angle between the first working surface D1 and the second working surface D2 of the light trap satisfy ;in, n The refractive index of the glass used to create light traps.

4. A miniature absorption light trap for a laser communication system according to claim 1, characterized in that: Define the ratio of the upper base to the height of the upper surface in a light trap as the shape ratio. Shape than satisfy ;in, The angle between the first working surface D1 and the second working surface D2 of the light trap. It is the distance from the incident point of the stray light beam on the first working surface D1 to the common edge of the first working surface D1 and the second working surface D2.

5. A miniature absorption light trap for a laser communication system according to claim 4, characterized in that: During its propagation inside the optical trap, the stray light beam first intersects with the second working surface D2 and undergoes a first total internal reflection; then, the stray light beam is reflected to the third working surface D3 and undergoes a second total internal reflection; then, the stray light beam is reflected to the third working surface D3 and undergoes a third total internal reflection; finally, the stray light beam exits the optical trap from the first working surface D1.

6. A miniature absorption light trap for a laser communication system according to claim 5, characterized in that: The distance the stray light beam travels from its incident point into the optical trap until the first total internal reflection occurs. for The distance the stray light beam travels from the first total internal reflection to the second total internal reflection. for in, The length of the bottom edge of the upper surface of the light trap; The distance the stray light beam travels from the second total internal reflection to the third total internal reflection. for in, The height of the upper surface of the light trap; The distance the stray light beam travels from the third total internal reflection to the point of exiting the light trap. for in, The length of the top base of the light trap's upper surface.

7. A miniature absorption light trap for a laser communication system according to claim 6, characterized in that: stray light suppression ratio of light traps for in, L The optical path length of the stray light beam as it propagates within the optical trap. ; The absorption coefficient of the vitreous body used to create the light trap.

8. A laser communication system, characterized in that, include: The system comprises an optical signal transmitting module, an optical signal receiving module, and a stray light suppression module; the stray light suppression module employs a miniature light-absorbing trap for a laser communication system as described in any one of claims 1 to 7. The optical signal transmitting module is used to transmit optical signals; the stray light suppression module is used to suppress stray light in the optical signal; and the optical signal receiving module is used to receive the optical signal after stray light suppression.

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