Tailored light emission from color centers in nanodiamond using self-assembled photonic crystals

At a Glance

Metadata	Details
Publication Date	2022-10-06
Journal	Frontiers in Nanotechnology
Authors	Sachin Sharma, ASHISH ASHISH, Rajesh V. Nair
Institutions	Indian Institute of Technology Ropar
Citations	2
Analysis	Full AI Review Included

Technical Documentation & Analysis: Tailored Light Emission from NV Centers in Nanodiamond

This document analyzes the research paper “Tailored light emission from color centers in nanodiamond using self-assembled photonic crystals” to highlight the material requirements and demonstrate how 6CCVD’s advanced MPCVD diamond products (SCD, PCD, BDD) and customization services provide essential solutions for replicating and advancing this quantum nanophotonics research.

Executive Summary

This research successfully demonstrated deterministic control over the spontaneous emission of Nitrogen-Vacancy (NV) centers in nanodiamonds (NDs) by integrating them with self-assembled photonic crystals (PCs).

LDOS Control: The study achieved significant modification of the Local Density of Optical States (LDOS) at room temperature by utilizing the photonic stopgap effect.
Emission Modulation: Quantified results show a 63% suppression and a 17% enhancement of NV center emission intensity at the stopgap wavelength (667 nm).
Lifetime Modification: The NV center lifetime (T₂) was successfully modified, confirming the strong wavelength-dependent LDOS fluctuation induced by the photonic structure.
Complementary Geometries: Control was achieved by simply switching between two complementary excitation geometries (rear-side and front-side), demonstrating a robust platform for emission tailoring.
Theoretical Consistency: The spectral redistribution of emission lifetime is consistent with the fundamental Barnett-Loudon sum rule.
Application Focus: The findings are crucial for developing robust NV center platforms for emerging quantum technologies (e.g., single-photon sources) and biophotonics.

Technical Specifications

The following hard data points were extracted from the research detailing the performance and material characteristics.

Parameter	Value	Unit	Context
NV Center Emission Suppression	63	%	Measured at 667 nm (rear-side geometry)
NV Center Emission Enhancement	17	%	Measured at 667 nm (front-side geometry)
NV⁰ Zero Phonon Line (ZPL)	576	nm	Characteristic spectral feature
NV⁻ Zero Phonon Line (ZPL)	639	nm	Characteristic spectral feature
Photonic Stopgap Wavelength (Sample B)	667	nm	Measured reflectivity peak (near-normal incidence)
Excitation Wavelength	532	nm	Frequency doubled Nd-YAG laser
Excitation Pulse Width	52	ps	Used for time-resolved emission measurements
Excitation Repetition Rate	10	MHz	Used for time-resolved emission measurements
NV Center Lifetime (T₂) Reference Sample	20.6 ± 0.2	ns	Measured in rear-side geometry
Nanodiamond Average Size	70	nm	Containing >300 NV centers per nanodiamond
Photonic Crystal Lattice Constants	277 (A), 406 (B)	nm	Determined by polystyrene microsphere size

Key Methodologies

The experiment relied on precise material assembly and complementary optical measurement techniques to isolate and quantify the LDOS effects.

Photonic Crystal Fabrication: Self-assembled colloidal method was used, allowing monodisperse polystyrene microspheres (refractive index 1.59) to evaporate in a temperature-controlled environment, resulting in face-centered cubic (fcc) packing.
Nanodiamond Integration: Nanodiamonds (70 nm average size, containing >300 NV centers) were drop-casted onto the top surface of the self-assembled photonic crystal samples.
Excitation Source: A frequency-doubled Nd-YAG laser (532 nm) was used for excitation. Time-resolved measurements utilized a pulsed mode (52 ps pulse width, 10 MHz repetition rate).
Low NA Objective: A low Numerical Aperture (NA = 0.10) objective was critical for emission collection to minimize the averaging of K-vectors, ensuring the stopgap effect at normal incidence remained prominent.
Complementary Measurement Geometries:
- Rear-side Geometry: Excitation beam passes through the substrate and photonic crystal before exciting the nanodiamonds (resulting in suppression at the stopgap).
- Front-side Geometry: Excitation beam directly excites nanodiamonds decorated on the PC surface (resulting in enhancement at the stopgap).
Lifetime Analysis: Emission decay spectra were fitted using a biexponential decay function to isolate the actual NV center lifetime (T₂) from components arising from graphitic impurities (T₁).

6CCVD Solutions & Capabilities

The successful implementation of NV center quantum platforms requires diamond materials with exceptional purity, low strain, and the ability to be precisely structured. 6CCVD provides the necessary MPCVD diamond substrates and engineering services to transition this research from ensemble nanodiamonds to integrated, deterministic quantum devices.

Applicable Materials

The research highlights the potential of NV centers for quantum applications, which demand the highest material quality to maximize spin coherence and minimize spectral diffusion.

Research Requirement	6CCVD Solution	Material Specification
High-Purity NV Host Material	Optical Grade Single Crystal Diamond (SCD)	Lowest strain and highest purity for generating isolated, high-coherence NV centers, essential for single-photon source development.
Large-Area Structured Platforms	Polycrystalline Diamond (PCD) Wafers	Available up to 125mm diameter, ideal for scaling up photonic crystal or waveguide integration via etching.
Integrated Sensing/Electrodes	Boron-Doped Diamond (BDD)	Can be used as conductive layers or electrodes for electrical charge state manipulation (NV⁰ <-> NV⁻), a critical requirement for robust quantum control.

Customization Potential

While the paper used self-assembled colloidal crystals, next-generation quantum devices require deterministic, etched photonic structures directly in the diamond. 6CCVD’s capabilities enable this transition.

Custom Dimensions and Thickness: 6CCVD supplies SCD and PCD plates/wafers with custom dimensions up to 125mm (PCD). We offer precise thickness control for both SCD and PCD from 0.1 µm to 500 µm, allowing researchers to select the optimal material thickness required for specific optical coupling and photonic crystal designs.
Advanced Metalization Services: The paper references plasmonic enhancement schemes. 6CCVD offers in-house custom metalization (including Au, Pt, Pd, Ti, W, Cu) on diamond surfaces. This capability is vital for integrating plasmonic structures or electrical contacts directly onto the diamond platform for enhanced LDOS control and charge state manipulation.
Structuring and Polishing: To create high-Q photonic crystal cavities or waveguides, ultra-smooth surfaces are mandatory. 6CCVD provides superior polishing services (Ra < 1 nm for SCD and Ra < 5 nm for inch-size PCD). We also offer custom laser cutting and etching support to fabricate deterministic photonic structures directly into the diamond substrate.

Engineering Support

6CCVD’s in-house PhD team specializes in MPCVD growth and post-processing techniques necessary for defect engineering. We can assist researchers in optimizing material selection and post-growth treatments (e.g., high-pressure/high-temperature annealing) for similar Quantum Nanophotonics and Spontaneous Emission Control projects.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

The defect centers in solid-state materials especially the nitrogen-vacancy (NV) centers in diamond have shown a tremendous potential for their utilization in quantum technology applications. However, they exhibit certain drawbacks such as the feeble zero phonon line with huge phonon contribution and the higher lifetime values. Here, we present a novel approach to control the spontaneous emission from NV centers in nanodiamond using engineered self-assembled photonic crystals. Using two complimentary emission measuring geometries at room temperature, we show a 63% suppression and 17% enhancement of NV center emission intensity using photonic stopgap, supported with simulations. The emission rates are modified in a broad spectral range of NV center emission and are consistent with the Barnett-Loudon sum rule. The results are crucial for emerging quantum technologies using NV centers in diamond.

Tech Support

Original Source

DOI: https://doi.org/10.3389/fnano.2022.951988

References

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2005 - Spectral and angular redistribution of photoluminescence near a photonic stop band [Crossref]
2012 - Engineered quantum dot single-photon sources [Crossref]
2021 - The diversity of three-dimensional photonic crystals [Crossref]
2013 - The nitrogen-vacancy colour centre in diamond [Crossref]