Deliverables description

The project plans 22 deliverables. The deliverables should coordinate the work of the consortium and inform the partners and the public of the work fulfilled in the different areas. There are certain types of deliverables such as reports, prototypes, demonstrators and others. The dissemination level of each deliverable (public to confidential) is defined in the deliverables list. The reports on the public deliverables can be accessed via the website without a password.

 

D1: Creation of NEMIS website

Delivery date: 11/06

Nature: Other

Dissemination level: Public

Objective: The project website serves to inform public about the scope of this research project and for internal communication amongst the partners.

Status: D1 has been achieved.

Abstract: The website of the NEMIS project can be reached at http://www2.wsi.tum.de/e26/nemis. It consists of a general description of the project, including the goals of NEMIS, detailed descriptions of the participants and their contributions to the work packages as well as the results archived so far. An internal, password protected area is used for the exchange of documents and information between the partners.

Report: The report can be viewed here.

 

D2: Report on specifications of VCSEL performance parameters

Delivery date: 02/07

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: This Deliverable specifies the device properties of the future VCSEL needed for gas sensing applications.

Status: D2 has been achieved.

Abstract: This report lists the agreed specifications of relevant VCSEL performance characteristics. They have evolved from a thorough analysis of the specific gas sensing applications we are aiming for in the NEMIS project, see appendix 1 and 2 for a concise description and requirements of the two pilot gas sensing applications utilizing photoacoustic spectroscopy (PAS) and wavelength modulation spectroscopy (WMS), respectively. Both VCSEL technology providers and industrial end-users within the NEMIS project have thus contributed to the definition of these VCSEL specifications.

 

D3: Definition, verification, unification of diagnostics and characterisation methods for VCSEL structures and devices (incl. ageing conditions)

Delivery date: 02/07

Nature: Report

Dissemination level: Public

Objective: This deliverable describes the methods for the characterisation of the substrates, the epitactically grown structures and the VCSEL.

Status: D3 has been achieved.

Abstract: The report on D3 discusses the methods for the characterization and the testing the VCSELs and VCSEL structures. The document includes the following issues:
- Preliminary material and technology characterizations
- Agreement on standard laser mounting
- Laser structure component parameters
- Final device parameters
- Ageing/Degradation parameters

Report: The report can be viewed here.

 

D4: VCSEL structure for emission at ~2.3 µm (+/- 100 nm) epitactically grown

Delivery date: 05/07

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: The epitaxial growth of the layer structure is one of the key components in the production of the VCSEL. This task focuses on the growth of dielectric Bragg mirrors, quantum wells and the intermediate layers of the device.

Status: D4 has been achieved.

Abstract: In the first milestone (M1) of NEMIS project, preliminary designs of microcavity VCSELs structures for the three target wavelengths (2.3 μm, 2.7 μm and 3.3 μm) were presented. Following the conclusions of this milestone, the present deliverable (D4) deals with the different microcavity structures developed by University Montpellier 2 and Walter Schottky Institut in order to manufacture electrically-pumped VCSEL devices emitting at 2.3 μm (+/- 100 nm). Considering the structures described in this report, the objective of this deliverable was achieved.
This deliverable is divided in two parts corresponding to the description of the different microcavity VCSELs structures respectively developed by University Montpellier 2 and Walter Schottky Institut.

 

D5: Report on first electrically pumped VCSEL (2.3 µm +/- 100nm)

Delivery date: 08/07

Nature: Report

Dissemination level: Public, will be kept restricted as long as no final version is present.

Objective: Deliverable 5 focuses on the developments on the VCSEL technology and the first results on electrically pumped devices.

Status: D5 has been partly achieved.

Abstract: The manufacturing of VCSELs involves an MBE growth and a multitude of processing steps. While the epitaxy was described in deliverable 4, the report on deliverable 5 shows the progress with the processing technology. In addition to that, the first device results are given. The features of the different approaches (monolytic, hybrid and buried tunnel junction-based VCSEL) are discussed in detail.
- For the monolithic structure, the first step consisted in the realization of Resonant-Cavity Light Emitting Diode (RC-LED), with a general structure similar to microcavity EP-VCSELs, to calibrate both the MBE growth conditions and the technological process. Then, full microcavity monolithic VCSEL devices were manufactured and tested.
- In parallel, a hybrid design was considered. Several dielectric material combinations were tested to optimize top Bragg mirror, then full EP-VCSELs structures were manufactured following the process described in D4.
- The BTJ structure demands special processing technologies. The manufacturing of the VCSELs involves 2 steps of epitaxial growth and 11 masks for optical lithography. The first growth step results in the basis layer structure consisting of a bottom Dielectric Bragg Reflector (DBR), a cavity with the active region and the tunneljunction.

Report: The report can be viewed here.

 

D6: First annual activity report

Delivery date: 08/07

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: The annual activity report gives an overview of the work done by the consortium during the first year of the NEMIS Project.

Status: D6 has been achieved.

Abstract: In the first year of the NEMIS project the partners performed the following work:
- creation and maintenance of the NEMIS website (all)
- considerable dissemination activity on national and international conferences (all)

-
definition of target device parameters of 2.3μm, 2.7μm and 3.3μm Sb-based VCSELs (all)
-
definition and unification of the relevant parameters and the characterisation methods for wafer, layer and device parameters as well as the ageing conditions (WSI/UM2/IOP/VERT/Omni)
- development of the epitaxial growth technique for 2.3μm GaSb-based VCSELs (WSI/UM2)
-
development of the chip technology for electrically pumped GaSb-based VCSELs (WSI/UM2)
-
design of the sensor application demonstrators (Omni/SAG)

In summary, the main achievements gained during the first project year are:
-
the NEMIS website, presenting the project worldwide
-
‘device specifications tables’ for 2.3μm, 2.7μm and 3.3μm VCSELs
- first viable electro-opto-thermal designs for the Sb-based VCSELs
-
development of reliable epitaxial growth and overgrowth techniques as required for the VCSEL fabrication
- active zones at 2.3μm and 2.7μm and semiconductor Bragg mirrors for entire 2-3.5μm wavelength range fabricated
-
dielectric and hybrid gold-dielectric mirrors
-
complete ~2.3μm VCSEL structures epitactically grown and processed to laser devices.

 

D7: Delivery of 10 electrically pumped room-temperature operating 2.3 µm VCSELs to WP 5

Delivery date: 11/07

Nature: Prototype

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: Fabrication (Epitaxy, processing and backend) of the VCSEL devices. Delivery of 10 packaged VCSEL to the consortium partners.

Status: D7 has been achieved.

Abstract: This report deals with the backend processing of the wafers as well as some results on the VCSEL devices made by UM2 and WSI. To test the performance for trace gas sensing in the application as well as to run some initial tests on reliability, 10 VCSELs have been shipped to the project partners (application: SAG, Omni, reliability: IOP).

 

D8: VCSEL structure for emission at ~ 2.7 µm (+/- 100nm) epitactically grown

Delivery date: 02/08

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: The epitaxial growth of the layer structure is one of the key components in the production of the VCSEL. This task focuses on the growth of dielectric Bragg mirrors, quantum wells and the intermediate layers of the device.

Status: D8 has been achieved.

Abstract: After the breakthrough on the GaSb-VCSEL, the following task is to modify the VCSEL design to reach the emission wavelength of 2.7µm and to develop a new active region at this wavelength. The results on the design, simulation and epitaxy of these new structures are presented in this report.

 

D9: Early demonstrator platform gas monitor based on WMS with absorbance sensitivity <10-4

Delivery date: 02/08

Nature: Demonstrator

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: Siemens aims at developing a gas monitor platform for hazardous gases (TLV detection) in industrial environments. The platform shall be useful for a maximum number of different gas species with minimum adaptation. Routes for low cost, low power supply, small size design are explored.

Status: D9 has been achieved.

Abstract: This report is about the early demonstrator platform gas monitor with wavelength modulation spectroscopy (WMS). Measurement results for verification of the correct mode of operation and an evaluation of sensor performance were made and are given in this report.

 

D10: Report on optimum VCSEL designs and their predicted performance

Delivery date: 02/08

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: Investigate possible improvements in the design of the BTJ- and monolythic VCSEL.

Status: D10 has been achieved.

Abstract: In this work two different VCSEL designs based on GaSb are proposed by the Walter Schottky Institute and Université Montpellier 2 to reach emission wavelengths of 2.3, 2.7 and 3.3 µm. In striving for further optimizing the proposed VCSEL designs, Chalmers has in this work investigated important optical properties via numerical simulations.

 

D11: VCSEL structure for emission at 3.3 µm

Delivery date: 08/08

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: The epitaxial growth of the layer structure is one of the key components in the production of the VCSEL. This task focuses on the growth of dielectric Bragg mirrors, quantum wells and the intermediate layers of the device.

Status: D11 has been achieved.

Abstract: After the successful development of BTJ-VCSELs at 2.3 µm by WSI and monolithic all-epitaxial VCSELs at 2.3 µm and 2.5 µm by UM2, a real breakthrough was performed in mid-IR VCSELs performances and both WSI and UM2 results represent the world state of the art. It should be noticed that BTJ and monolithic structures can be adapted for emission at longer wavelengths on the condition of modifying the thicknesses of the layers which constitute the Bragg mirrors and of developing a powerful active zone. The following task of NEMIS partners is thus to develop these two “building blocks” which are the key parts for performant VCSELs structures. The results on the design, simulation and epitaxy of these key parts are presented in this deliverable.

 

D12: Report on comparison of device concepts for oxide-confined and BTJ GaSb-VCSELs

Delivery date: 08/08

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: A comparison of the device characteristics between the BTj and monolytic design.

Status: D12 has been achieved.

Abstract: In the NEMIS-project, two designs for the GaSb-based VCSEL are investigated: The buried tunnel junction (BTJ) and the monolithic design. In this report, the characteristics of devices with those two designs are compared.

 

D13: Second annual activity report

Delivery date: 08/08

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: The annual activity report gives an overview of the work done by the consortium during the second year of the NEMIS Project.

Status: D13 has been achieved.

Abstract:

In the second year of the NEMIS project the partners performed the following work:
continued maintenance of the NEMIS website (all)
introduction of a sharepoint server for the exchange of internal documents between the partners (WSI)
considerable dissemination activity on national and international conferences (all)
extensive numerical simulations of the optical properties of selected VCSEL designs to provide guidelines for design improvements (Chalm/WSI)
establishing epitaxial technology for GaSb-based VCSELs in the 2.3-3.3μm wavelength range (UM2 and WSI)
developing improved electrically pumped VCSEL structures for the GaSb-material system (UM2 and WSI)
packaging cw single-mode and tunable VCSELs (WSI/UM2/IOP/VERT)
preliminary lifetime and noise measurements on packaged VCSELs (IOP/VERT/UM2/WSI)
characterizing optical constant of relevant compound semiconductors (IOP/UM2/WSI)
development of WMS- and PAS-sensors using VCSELs (SAG/Omni/VERT/UM2/WSI)

In summary, the main achievements gained during the second project year are:
first realisation (worldwide) of single-mode and tunable electrically pumped 2.3μm GaSbbased VCSELs (UM2 and WSI)
first realisation (worldwide) of electrically pumped VCSEL at 2.5μm (UM2)
development of the epitaxial growth technique for 2.7μm GaSb-VCSELs (WSI and UM2)
effects of VCSEL design parameters on modal properties and diffraction loss established (Chalm/WSI)
optical constants of GaSb and other related compounds on test samples and device structures determined for VCSEL simulations and design (IOP/Chalm/WSI/UM2)
VCSEL-based wavelength-modulation spectroscopy (WMS) sensor for CO at 2.33μm demonstrated (WSI/VERT/SAG)
NH3-spectra at 2.35μm measured with tunable VCSEL (Omni/WSI/VERT)

 

D14: Demonstrator of ammonia sensor based on PAS

Delivery date: 02/09

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: The implementation of GaSb-based VCSELs in a PAS system and their testing for application suitability.

Status: D14 has been achieved.

Abstract: In this report, the design and improvements of the PAS cell and control are described. The GaSb-based VCSEL developed in WP2 and 3 is implemented in a PAS system and tested for this application. The VCSEL show principle suitability but still lack output power to reach the desired detection limit.

 

D15: Measurement and characterisation of laser structures.

Delivery date: 03/09

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: Measurement and characterization of VCSEL properties.

Status: D15 has been achieved.

Abstract: With the support of several NEMIS partners, VCSEL devices were characterized, leading to a better understanding of their properties. This includes measurements during the production (e.g. spectral measurements), the characterization of complete VCSEL structures (spectra, electrical noise measurements), but also measurements of basic material properties, such as refractive indices.

 

D16: Improved demonstrator platform gas monitor.

Delivery date: 11/09

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: Presentation of an improved (fully digital) demonstrator platform gas monitor.

Status: D16 has been achieved.

Abstract: This report is about the improved (fully digital) demonstrator platform gas monitor with wavelength modulation spectroscopy (WMS). Measurement results for verification of the correct mode of operation and an evaluation of sensor performance were made and are given in this report.

 

D17: Report on analysis of VCSEL performance.

Delivery date: 01/10

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the commission services)

Objective: Detailed report on the VCSEL performance during the full project duration.

Status: D17 has been achieved.

Abstract: Deliverable 17 reports on the analysis of the VCSEL performance during the full project duration. A multiphysics quasi-three-dimensional VCSEL model originally developed to study 850 nm oxide-confined VCSELs was adapted to being used for long wavelength BTJ-VCSELs. Output-power and wavelength vs. current characteristics for devices with and without a shallow surface-relief have been simulated, as well as the optical field distribution, current flow in the device and heat distribution. The results provide feedback for further design optimization.

 

D18: Final report on device technology and fabrication techniques for the VCSEL devices.

Delivery date: 01/10

Nature: Report

Dissemination level: Public

Objective: Reporting on the fabrication techniques of GaSb-based VCSELs developed at WSI and UM2.

Status: D18 has been achieved.

Abstract: All fabrication techniques for the realization of GaSb-based vertical-cavity surface-emitting lasers are demonstrated in this report. Two different concepts were developed by partners WSI and UM2, the BTJ-VCSEL and mesa-constricted VCSEL, respectively. In the first design, a twofold epitaxial growth process is used and lateral current confinement and index guiding in the device are accomplished by means of a structured Buried Tunnel Junction. The latter design is an all-epitaxial VCSEL with a BTJ in order to improve device performance.

Report: The report can be viewed here.

 

D19: Characterisation and tests of laser devices for gas sensing.

Delivery date: 01/10

Nature: Report

Dissemination level: Confidential, only for members of the consortium (including the Commission Services)

Objective: Final reporting of characterisation of the VCSELs from WP4 to VCSEL developers.

Status: D19 has been achieved.

Abstract: The NEMIS mid-infrared semiconductor lasers were measurement from the point of view of their lifetime, light output, threshold behaviour, mode spectrum quality, far field emission, noise, V/A and W/A characteristics.

 

D20: Demonstrator of 13CO2/12CO2 sensing system based on PAS with 0.1% resolution

Delivery date: 01/10

Nature: Report

Dissemination level: Restricted to a group specified by the consortium (including the Commission Services)

Objective: Reporting on the final PAS measurements.

Status: D20 could not be achieved completely due to the withdrawal of partner OMNISENS from the project on 31st August 2009.

Abstract: In this report, the design of a dual photoacoustic cell is described. It is specifically adapted to the use of VCSEL while providing the capability of measuring CO2 isotopic ratio.

 

D21: Report on analysis of VCSEL performance and on their use in gas analysis systems

Delivery date: 01/10

Nature: Report

Dissemination level: Public

Objective: Reporting on the final VCSEL performance.

Status: D21 has been achieved.

Abstract: During the project the proof of existence for GaSb and InP based 2.3 µm VCSEL has been provided and performance has been considerably improved during NEMIS . The performance of these lasers with respect to gas sensing has been evaluated at SAG. A crucial parameter is the smoothness of the P(I) curve, as any deviation from the ideal behavior results in a sensitivity loss of the gas sensor. With regard to smoothness the new 2.3 µm InP- and GaSb-based lasers are still inferior to state of the art 1.5 µm VCSELs. Only selected devices nearly reach the targeted smoothness in the order of 10-5. Regarding operating temperature range, output power, tuning coefficients and FM response GaSb VCSELs are superior to InP-based devices. However both types fulfill the requirements for gas sensing. Selected InP- and GaSb VCSEL with smooth P(I) characteristics have been tested in complete stand alone gas sensors with similar results. The detection limit for CO is 3 ppm and 4 ppm for the InP resp. the GaSb VCSEL which is close to the expected values implying that the laser noise is almost similar low in both types. In summary it might be concluded that the potential of the new VCSELs is clearly visible, but a great deal of development work has to be conducted especially on the smoothness of the P(I) characteristics on the way to a reliable commercial device for gas sensing.

Report: The report can be viewed here.

 

D22: Third year annual report

Delivery date: 02/10

Nature: Report