Highly efficient second-harmonic generation in a double-layer thin-film lithium niobate waveguide

Yuan Li; Xiuquan Zhang; Lutong Cai; Lin Zhang

doi:10.1117/1.APN.3.6.066009

Advanced Photonics Nexus, Volume. 3, Issue 6, 066009(2024)

Highly efficient second-harmonic generation in a double-layer thin-film lithium niobate waveguide

Yuan Li¹, Xiuquan Zhang², Lutong Cai^1、*, and Lin Zhang^1,3、*

¹Tianjin University, School of Precision Instruments and Opto-Electronics Engineering, State Key Laboratory of Precision Measuring Technology and Instruments, Key Laboratory of Opto-Electronic Information Technology of Ministry of Education, Tianjin Key Laboratory of Integrated Opto-Electronics Technologies and Devices, Tianjin, China

²Shandong University, Ministry of Education, Key Laboratory of Laser and Infrared System, Qingdao, China

³Peng Cheng Laboratory, Shenzhen, China

show less

Figures & Tables(6)

$(a) Schematic of the waveguide cross section. (b) Dominant electric field component (Ez) of the TE00 mode at the fundamental wavelength. (c) Dominant electric field component (Ez) of the TE01 mode at the SH wavelength. Both d33 and Ez of the TE01 mode have the opposite signs across the polarization-reversed double-layer LN. (d) Dependence of the effective refractive indices of the interacting waveguide modes on wavelength, with PM at 1552.2 nm. (e) Calculated ηnorm of the double-layer LNOI waveguide as a function of h1. (f) Black: ηnorm versus the total thickness (H) of the waveguide. Red: ηnorm versus the waveguide loss. (g) Effective refractive indices of the interacting waveguide modes versus the width of the waveguide when H is 450 nm. (h) Scanning electron microscopy (SEM) image of the waveguide sidewall.$

Fig. 1. (a) Schematic of the waveguide cross section. (b) Dominant electric field component ( $E_{z}$ ) of the ${TE}_{00}$ mode at the fundamental wavelength. (c) Dominant electric field component ( $E_{z}$ ) of the ${TE}_{01}$ mode at the SH wavelength. Both $d_{33}$ and $E_{z}$ of the ${TE}_{01}$ mode have the opposite signs across the polarization-reversed double-layer LN. (d) Dependence of the effective refractive indices of the interacting waveguide modes on wavelength, with PM at 1552.2 nm. (e) Calculated $η_{norm}$ of the double-layer LNOI waveguide as a function of $h_{1}$ . (f) Black: $η_{norm}$ versus the total thickness ( $H$ ) of the waveguide. Red: $η_{norm}$ versus the waveguide loss. (g) Effective refractive indices of the interacting waveguide modes versus the width of the waveguide when $H$ is 450 nm. (h) Scanning electron microscopy (SEM) image of the waveguide sidewall.

Download full size

View in Article

Fig. 2. Experimental setup for device characterization. PC, polarization controller; EDFA, erbium-doped fiber amplifier; WG, waveguide; AL, aspherical lens.

Download full size

View in Article

Fig. 3. (a) Measured $η_{norm}$ (black) as a function of wavelength. Maximum $η_{norm}$ of $9600 % W^{- 1} {cm}^{- 2}$ at 1485.7 nm is observed. The red dotted and blue dashed curves correspond to simulations with ideal and corrected models, respectively. The inset shows the top-view optical micrograph of the scattered SH signal at the waveguide facet. (b) The transmission spectrum of a microring resonator is used to extract waveguide loss, with experimental data shown in black and a fitting curve shown in red. (c) PM wavelength versus the top width of the waveguide.

Download full size

View in Article

Fig. 4. (a) Measured (green) and simulated dependence of SHG power (at the output facet of the waveguide) on the pump power (at the input facet of the waveguide). Red dashed line: simulation without considering pump depletion and waveguide loss. Black dashed line: simulation with considering pump depletion only. Blue dashed line: simulation with considering both pump depletion and waveguide loss. The inset shows the input–output power relation in the low-power regime. (b) Measured and simulated $η_{abs}$ ( $η_{abs} = P_{2 ω} / P_{ω}$ ) of SHG as a function of the pump power extracted from (a).

Download full size

View in Article

Fig. 5. Measured and simulated PM wavelengths as a function of temperature, in good agreement. Also, this exhibits a desirable thermal tunability.

Download full size

View in Article

Table 1. Comparison of SHG waveguides in LNOI working at telecommunication band.

View table

View in Article

Table 1. Comparison of SHG waveguides in LNOI working at telecommunication band.


Platform	PM type	Length (mm)	Pump power (mW)	$η_{abs}$ (%)	$η_{SHG}$ ( $% W^{- 1}$ )	$η_{norm}$ ( $% W^{- 1} {cm}^{- 2}$ )	SH power (mW)
PPLNOI²¹	QPM	5	NA	NA	40^a	160	NA
PPLNOI²²	QPM	4	220	53	416^a	2600	117
PPLNOI²⁸	QPM	0.6	NA	NA	16.6^a	4600	NA
PPLNOI²⁹	QPM	21	20	82.5	9500	2154	16.5
LNOI³⁰	BPM	20	25^a	0.3^a	10.7	2.7	0.067^a
LNOI³²	MPM	8	NA	NA	4.7	7.4	NA
LNOI³³	MPM	0.9	0.737	$4.5 \times 10^{- 5}$ ^a	0.06	6.9	$3.05 \times 10^{- 7}$
LNOI³⁴	MPM	3.2	NA	NA	5^a	48	NA
LNOI³⁶	MPM	2.35	NA	NA	36	650	NA
LNOI³⁹	MPM	1.2	0.126^a	0.01^a	79.8	5540	$1.26 \times 10^{- 5}$ ^a
LNOI (this work)	MPM	10	200	85	9600	9600	170

Tools

Get Citation

Copy Citation Text

Yuan Li, Xiuquan Zhang, Lutong Cai, Lin Zhang, "Highly efficient second-harmonic generation in a double-layer thin-film lithium niobate waveguide," Adv. Photon. Nexus 3, 066009 (2024)

Download Citation

EndNote(RIS)BibTex Plain Text

Set citation alerts for article

Save article for my favorites

Paper Information

Category: Research Articles

Received: Jul. 5, 2024

Accepted: Oct. 21, 2024

Published Online: Nov. 8, 2024

The Author Email: Lutong Cai (lutong_cai@tju.edu.cn), Lin Zhang (lin_zhang@tju.edu.cn)

DOI:10.1117/1.APN.3.6.066009

CSTR:32397.14.1.APN.3.6.066009

Topics

laser devices and laser physics

Lasers and Laser Optics

Laser physics

laser manufacturing

Instrumentation, Measurement and Metrology