US 12,294,198 B2
Surface emitting laser with hybrid grating structure
Chien Hung Pan, Hualien County (TW); and Cheng Zu Wu, Hsinchu County (TW)
Assigned to TrueLight Corporation, Hsinchu (TW)
Filed by TrueLight Corporation, Hsinchu (TW)
Filed on Jan. 30, 2024, as Appl. No. 18/427,644.
Application 18/427,644 is a continuation of application No. 18/199,960, filed on May 21, 2023, granted, now 11,967,800.
Application 18/199,960 is a continuation of application No. 17/033,763, filed on Sep. 26, 2020, granted, now 11,791,609, issued on Oct. 17, 2023.
Prior Publication US 2024/0413608 A1, Dec. 12, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H01S 5/11 (2021.01); H01S 5/12 (2021.01); H01S 5/183 (2006.01); H01S 5/185 (2021.01); H01S 5/32 (2006.01)
CPC H01S 5/11 (2021.01) [H01S 5/1215 (2013.01); H01S 5/124 (2013.01); H01S 5/183 (2013.01); H01S 5/185 (2021.01); H01S 5/3211 (2013.01); H01S 2304/04 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A surface emitting laser, comprising:
a semiconductor-laminated structure, capable of generating a laser light with a laser wavelength when receiving a predetermined current; the laser light being emitted vertically upward from a light-emitting surface of the semiconductor-laminated structure; the light-emitting surface being located on a top surface of the semiconductor-laminated structure; and
a photonic crystal layer, formed on the semiconductor-laminated structure; the photonic crystal layer including a plurality of micro photonic crystal structures distributed and arranged along both a first horizontal direction and a second horizontal direction; the second horizontal direction is perpendicular to the first horizontal direction;
wherein, the photonic crystal layer is divided into at least one first photonic crystal region and at least one second photonic crystal region along both the first horizontal direction and the second horizontal direction; each of the first and second photonic crystal regions contains a plurality of the micro photonic crystal structures respectively;
wherein, a photonic crystal period of the micro photonic crystal structures in the first photonic crystal region is in accordance with the following mathematical formula:

OG Complex Work Unit Math
in addition, another photonic crystal period of the plurality of micro photonic crystal structures in the second photonic crystal region is in accordance with the following mathematical formula:

OG Complex Work Unit Math
wherein, ∧ is a length of photonic crystal period; λ is a wavelength of the laser light; neff is an equivalent refractive index of semiconductor waveguide; both m and o are integrals; m is not equal to o; and o is an even multiple of m;
wherein, the light-emitting surface is defined by the second photonic crystal region;
wherein the photonic crystal layer comprises two phase-shift photonic crystal structures; one of the phase-shift photonic crystal structures is located near a middle of the second photonic crystal region in the first horizontal direction, the other phase-shift photonic crystal structure is located near another middle of the second photonic crystal region in the second horizontal direction; the width of each of the phase-shift photonic crystal structures can provide a phase-difference distance, such that a phase difference is formed between the micro photonic crystal structures located on both sides of the phase-shift photonic crystal structure along the first horizontal direction and the second horizontal direction respectively; the phase-difference distance provided by the phase-shift photonic crystal structure is one quarter of the laser wavelength.