Laser-induced luminescent centers in diamond - influence of exposure and duration of short laser pulses
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2022-01-01 |
| Journal | Оптика и спектроскопия |
| Authors | П. А. Данилов, S. I. Kudryashov, A. O. Levchenko, E. A. Oleynichuk, O. E. Koval’chuk |
| Institutions | VNIIGIS, P.N. Lebedev Physical Institute of the Russian Academy of Sciences |
| Analysis | Full AI Review Included |
Technical Documentation & Analysis: Laser-Induced Luminescent Centers in Diamond
Section titled “Technical Documentation & Analysis: Laser-Induced Luminescent Centers in Diamond”This document analyzes the research on laser-induced NV center formation in diamond using ultrashort pulses and outlines how 6CCVD’s advanced MPCVD diamond materials and customization capabilities can accelerate and scale this research for quantum technology and micro-marking applications.
Executive Summary
Section titled “Executive Summary”The research successfully demonstrates the precise, volume-localized formation of negatively charged Nitrogen Vacancy (NV) centers in diamond using ultrashort laser pulses, a critical step for quantum sensing and optical memory applications.
- Core Achievement: Creation of high-contrast, luminescent NV centers (peak emission ~640 nm) deep within the diamond volume (~200 µm) using 515 nm ultrashort laser pulses.
- Method Validation: The ultrashort pulse technique (0.3-2.4 ps duration) avoids visible structural damage or graphitization, confirming its suitability for high-integrity defect engineering.
- Yield Optimization: Luminescence yield was found to be linearly dependent on laser exposure time (pulse count) for energies up to 600 nJ.
- Optimal Parameters: The highest luminescence amplitude was achieved using a 1.0 ps pulse duration, providing a key optimization parameter for future laser writing recipes.
- Material Requirement: The study utilized natural IaA diamond, but the precision required for scaling this technology necessitates the superior purity and controlled nitrogen content offered by 6CCVD’s Single Crystal Diamond (SCD).
- Application Potential: The technique is confirmed as a promising method for “invisible” micro-marking and the creation of stable quantum registers.
Technical Specifications
Section titled “Technical Specifications”The following hard data points were extracted from the experimental section detailing the laser processing and material characteristics:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Laser Wavelength (SH) | 515 | nm | Second Harmonic Generation (SHG) |
| Pulse Duration Range | 0.3 - 2.4 | ps | Range tested for defect formation |
| Repetition Rate | 100 | kHz | Constant laser frequency |
| Processing Energy Range | 60 - 600 | nJ | Energy used per pulse for writing |
| Exposure Time Range | 30 - 360 | s | Corresponds to (3-36) * 106 pulses per point |
| Focal Depth | ~200 | µm | Depth of NV center formation in volume |
| Focal Spot Size (R1/e) | 2.2 ± 0.2 | µm | Spot size in air at focal plane |
| Diamond Type Used | IaA-type | N/A | Natural, colorless, transparent |
| NV Center Luminescence Peak | ~640 | nm | Maximum amplitude observed |
| N3 Center Absorption Peak | 415 | nm | Characteristic of the IaA sample material |
| Raman Pumping Wavelength | 532 | nm | Used for confocal spectroscopy analysis |
Key Methodologies
Section titled “Key Methodologies”The experiment focused on direct laser beam writing using precise control over pulse duration and exposure time to induce point defects.
- Laser Setup: Second harmonic radiation (515 nm) generated from a femtosecond ytterbium fiber laser was used.
- Pulse Control: A built-in compressor varied the pulse duration across the range of 0.3 ps to 2.4 ps.
- Focusing: Laser radiation was focused to a depth of approximately 200 µm using a micro-objective (NA = 0.25).
- Sample Movement: The IaA-type diamond sample was fixed on a three-coordinate motorized Standa platform with a minimum movement step of 150 nm.
- Defect Writing: Point defects were formed in a matrix pattern (12 µm spacing) at various combinations of energy (60-600 nJ) and exposure time (30-360 s).
- Pre-Characterization: Transmission spectra (200-1100 nm) were measured to confirm the presence of N3 centers (415 nm).
- Post-Processing Analysis: Visualization and luminescence analysis were performed using 3D scanning confocal Raman spectroscopy with a 532 nm continuous pump laser.
- Structural Integrity Check: Optical microscopy and Raman spectroscopy confirmed the absence of graphitization or visible damage in the processing areas.
6CCVD Solutions & Capabilities
Section titled “6CCVD Solutions & Capabilities”6CCVD specializes in providing the high-purity, engineered diamond materials necessary to transition research like this from natural samples to scalable, reproducible quantum devices. The use of MPCVD diamond offers superior control over nitrogen concentration, which is the primary limiting factor in NV center yield and coherence.
Applicable Materials
Section titled “Applicable Materials”To replicate and extend this research, 6CCVD recommends the following materials, offering superior performance and scalability compared to natural IaA diamond:
| Material Grade | Description & Application | 6CCVD Advantage |
|---|---|---|
| Optical Grade SCD (Low N) | Ultra-high purity Single Crystal Diamond (SCD) with extremely low intrinsic nitrogen (< 1 ppb). | Ideal for creating high-coherence, isolated NV centers (Type IIa equivalent) where precise, post-growth nitrogen implantation is preferred. |
| Engineered SCD (Controlled N) | SCD grown with controlled, low-level nitrogen incorporation (e.g., 1-10 ppm). | Provides a uniform, controlled density of nitrogen precursors, optimizing the yield of NV centers created by laser writing or subsequent annealing. |
| Polished PCD Wafers | Polycrystalline Diamond (PCD) wafers up to 125 mm diameter. | Suitable for large-area micro-marking applications where high throughput and large substrate size are critical, leveraging the technique’s proven resistance to graphitization. |
Customization Potential
Section titled “Customization Potential”The research utilized a small 4 mm natural cube. 6CCVD’s capabilities enable the scaling of this technology to industrial and advanced research levels:
- Custom Dimensions: We supply SCD plates up to 10x10 mm and PCD wafers up to 125 mm in diameter, far exceeding the dimensions of the natural sample used.
- Thickness Control: SCD and PCD layers are available from 0.1 µm up to 500 µm, with substrates up to 10 mm thick, providing ample volume for deep laser writing (e.g., the 200 µm depth demonstrated).
- Superior Polishing: We guarantee SCD surfaces with roughness Ra < 1 nm, essential for minimizing scattering and ensuring precise focusing of ultrashort pulses for volume writing.
- Metalization Services: For researchers transitioning to functional quantum devices, 6CCVD offers in-house metalization (Au, Pt, Pd, Ti, W, Cu) for creating electrical contacts or alignment markers on the diamond surface.
Engineering Support
Section titled “Engineering Support”6CCVD’s in-house PhD team provides expert consultation on material selection and optimization for advanced projects. We can assist researchers in determining the optimal nitrogen concentration and material thickness required to maximize NV center yield and coherence time for similar ultrashort pulse defect engineering projects.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.
View Original Abstract
The optical properties of point luminescent centers formed in the volume IaA-type natural diamond under the action of ultrashort laser pulses in the visible range (515 nm) with durations of 0.3-2.4 ps were investigated. The analysis using confocal Raman spectroscopy demonstrates the formation of nitrogen vacancy centers (NV) and there are no graphitization traces in processing areas. The luminescence amplitude of NV centers depends linearly on the exposure time at different durations of ultrashort laser pulses. Keywords: ultrashort laser pulses, luminescence, luminescent centers in diamond, NV centers.