An in-depth analysis of reflections in MMI couplers using optical low-coherence reflectometry: design optimization and performance evaluation

Multimode interference coupler based on general interference for integrated optical and quantum optic devices: a review

“…Since the introduction of MMI couplers, extensive studies have been carried out using silicon based materials [7-11, 29-46, 56-66] III-V semiconductors [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], polymers [47][48][49][50]67] and lithium niobate (LiNbO 3 ) [51], for its realization in integrated optics circuits. The materials used in integrated optics are of either low index contrast (e.g.…”

“…silica on silicon [29][30][31][32][33][34][56][57][58][59][60], polymer [47][48][49][50], LiNbO 3 [49]) or high index contrast (e.g. GaAsInP [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28], Silicon oxinitride (SiON) [9-11, 45, 46], SOI [35-44, 61-66, 99]. Out of these materials, compact waveguide devices are possible to fabricate by using SiO 2 /SiON [7][8][9][10][11], SOI [35][36][37][38][39][40][41][42][43][44] and InP/GaAsInP [1,…”

“…Out of these materials, compact waveguide devices are possible to fabricate by using SiO 2 /SiON [7][8][9][10][11], SOI [35][36][37][38][39][40][41][42][43][44] and InP/GaAsInP [1,2] material. Although SOI material provides higher index contrast than other waveguide materials, but it has higher propagation loss (∼ 3.2 dB cm −1 ) [83] and higher chip to fiber loss (∼ 2-4 dB/facet) [83] than those of SiO 2 /SiON material [9][10][11] and InP/GaAsInP [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”

Distributed bonding interface characterization of composite laser crystal based on optical low-coherence reflectometry

“…OLCR originated from the theory of partial coherence [10] and was practically developed and applied in the field of fiber optic sensing [11] and fiber fault diagnosis [12][13] in the 1980s. In recent years, it has gradually expanded to the testing of polarization-maintaining fibers [14] , active fiber [15][16] , fiber optic devices ( FBGs [17] , couplers [18] , etc. ), and bulk optical devices (such as surface inspection [19] and thin film thickness measurement [20] ).…”

Local complex reflectivity in optical waveguides

“…Knowledge of the complex response in reflection or transmission is hence of crucial importance for the design and the optimization of dispersive optical devices including fiber Bragg grating dispersion compensators and filters, 2-4 absorbing reflector, 5 microcavity and other slow wave structures, 6,7 delay line, etc. Even for nonresonant structures, such as splitter waveguides or multimode interferometer ͑MMI͒, 8 the phase information naturally allows for a more detailed analysis of the given structure.…”