---
# System prepended metadata

title: ':closed_book:Project Tasks'
tags: [Tasks, Stuff]

---

:closed_book:Project Tasks
===
###### tags: `Tasks` `Stuff`

:::info
### :notebook:Quantify Internal Quantum Efficiency for new Epi ($\eta_i$)
> Basically fabricate broad area Fabry-Perot lasers (width >50$\mu$m)
> ==$f_r^2 = \frac{1}{4\pi^2}\frac{v_ga}{qV_p}\eta_i(I-I_{th})$==

___
> ***:dart: NEW MASK UPDATE*:** **https://hpe-my.sharepoint.com/:u:/p/stanley_cheung/EdDaxbND8GlHpGeH8pybWEwBuCLMw_F2v7Xfsf1W3gniPA?e=Jdp017**
___

- [x]Review current mask with David for cutback structures:
**https://hpe-my.sharepoint.com/:u:/p/stanley_cheung/EexV2njTUM1Om11Q5NOjT8UB5yjSzQUVRdHySGJJoH1BSg?e=Vxy6Oc**
- [x]David determined that we need a new mask (4 layers):
    1. layer1: p-contact 50um wide: wet etch H2SO4:H2O2:H20 (1:5:15) to InGaP
    2. layer2: protection layer for TLM with PR
    3. layer3: wedding cake structure to access n-contact (dry or wet etch)
    4. layer3: n-contact 50um wide 


8/7/2019
![](https://i.imgur.com/0S20sea.jpg)


- [x]Ordered masks from Compugraphics (1st 2 layers ship on 8/20)
- [ ]Update fab sheet and revise traveler with David and Chuck:
**https://hpe-my.sharepoint.com/:p:/p/stanley_cheung/EWaOOKI_ic9MvHT8zKfylTcBJgsIs2AyUDfhtqk1pJEKjw?e=c7JTjX**
- [x]Finalize pulsed current source (LDP-3840B): 
**https://www.newport.com/c/pulsed-laser-diode-drivers**
- [ ]Fabricate at HP Labs and thin/scribe at Oepic :scissors: 
- [x]Decided to build separate experimental setup with pulsed current driver
- [x]Setup build: Purchase TEC, peltier, thermistor, tube 'scope, camera, rails, etc.
- [x]Need a computer for data acquisition (still getting approval from Peter)
- [ ]Epi material arrival still up in the air, but we can still use existing FPs to test (need to get some back from Guan-Lin at Berkeley)

- (after 1st mask): etch down to InGaP H2SO4:H2O2:H20 (1:5:15) cool down to RT, 30 min.
- (after 2nd mask): etch down to InGaP H2SO4:H2O2:H20 (1:5:15) cool down to RT, 30 min.
- 4 or 5 lengths for the FP laser cutback


:::

:::info
### :notebook:Silicon nitride CWDM AWGs and Lattice Filters
> Tape-out from Ligentec (150nm $Si_3N_4$)
___
- :dart: MEASUREMENTS: **https://hpe-my.sharepoint.com/:p:/p/stanley_cheung/ETanrkG0OiNFjpmoIEvUSccBi3bfGhe4jK1xBKAPGFyv5Q?e=cgNWrN**
___
- :dart: LATTICE FILTER DESIGNS: **https://hpe-my.sharepoint.com/:p:/p/stanley_cheung/Ece3f9EvPd9Fqw5nXTEWnEQBnOaYW5uZ668K8hVdPBcK-w?e=QeaNdw**
___
- :dart: AWG DESIGNS: **https://hpe-my.sharepoint.com/:p:/p/stanley_cheung/ESsJjV5vgBROpRJTwKn3JUsBtuSABAZ0y05812V0lUWdsw?e=HKYUwr**
___

- [x]Minor builds to existing setup
- [x]Characterize same devices on different dies (7 dies) and obtain some statistics
    * Flat-top and normal AWG
- [x]Plot data from past experiments and analyze
- [x]Need to purchase tube 'scope and camera :moneybag::moneybag::moneybag::dollar:
- [x]Obtained wafer uniformity map ($\mu_{mean}$=148.2nm, $\sigma$=2.3nm) and CD field map ($\mu_{mean}$=238nm, $\sigma$=13nm)
- [x]Characterize passband temperature shift (pm/$^\circ$C)
    -- **AWG (54 pm/$^\circ$C)** 
    -- **MZI Lattice (17 pm/$^\circ$C)**
- [ ]Characterize broadband directional couplers & ~~waveguide losses (maybe difficult--lack of spiral lengths)~~ 
    -- **Waveguide loss = 0.3-0.4 dB/cm** at 1064nm for WG width=1.7um
- [x]Literature search for grating couplers and edge couplers: **https://hackmd.io/LKF0NdPrTnmjVlx-QTs7ug?both**
:::

:::info
### :notebook:HCG with Au metal assisted mirror
> Sims and fab with RAITH
___
- :dart: DESIGNS: **https://hpe-my.sharepoint.com/:p:/p/stanley_cheung/EcElrEudd-9Kr8FdvSaawwgBkMgFPj2nCeN8DwVLWSC_XA?e=11tGZw**
___
- :dart: MEASUREMENTS: **https://hpe-my.sharepoint.com/:p:/p/stanley_cheung/EYOWAfKTfF1Do3vEH1SS-6EBjhPTtOQGixjbQ1J961PQtA?e=xXGALb**
___
- [x]New simulations: :computer: :computer: :computer: 
    1. GaAs HCG/infinite SiO2 :heavy_check_mark:
    2. GaAs HCG/finite SiO2 :heavy_check_mark:
    3. GaAs HCG/finite SiO2/Au :heavy_check_mark:
    4. oxididzed AlxGa1-xAs/GaAs HCG/infinite SiO2 :heavy_check_mark:
    5. Al0.6Ga0.4As/GaAs HCG/air cladding :heavy_check_mark: 
    6. Al0.6Ga0.4As/GaAs HCG/finite SiO2 :heavy_check_mark:
    7. Al0.6Ga0.4As/GaAs HCG/finite SiO2/Au :heavy_check_mark:
- [ ]START MAKING MHCG/dielectric/Au sample with RAITH e-beam ASAP!!!!
- [ ]CHARACTERIZE!!!!
:::

:::info
### :notebook:BTO/ITO plasmonic modulator/ MOS effect
> for external VCSEL modulation
___
- :dart: DESIGNS: **https://hpe-my.sharepoint.com/:p:/p/stanley_cheung/EZqOWudcN-RDt3QJYOoUMAwB4m04ID3uW4DpBbznBNEOVg?e=uKu7k5**
___

- [x]Literature search
- [x]Perform initial design calculations for $r_{eff}$, $V_\pi L$, $\Gamma_{conf}$, electrode gap, etc.
- [x]Calculate ITO complex permittivity from Drude-Lorentz model and translate values to refractive index change and loss vs. wavelength vs. carrier concentration
- [ ]Look into implementing models in Lumerical with Drude-Lorentz
```flow
st=>start: Start
e=>end: End
op=>operation: Calculate Drude Lorentz
op2=>operation: Calculate confinement factor
in 10nm charge accumulation layer
op3=>operation: Vary Si3N4/ITO, height, width

st->op->op2->op3->e
```
:::


